Abstract:
A light diffusing device for use in photodynamic therapy has a progressively distally increased exposed amount of core fiber defining a light emitting section. Excessive light energy emission is thus prevented access to proximal locations and provides an increased amount of available light energy at distal locations, thus permitting an even emission of light energy along the light emitting section.

Description:
GOVERNMENT LICENSE RIGHTS 
       [0001]    The U.S. government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided by the terms of Grant No. 2R44 A1041866-02A2 awarded by the National Institute of Health: National Institute of Allergy and Infectious Diseases. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to devices used for light transmission as are used in photodynamic therapy to deliver light energy to a treatment site. 
       BACKGROUND 
       [0003]    Photodynamic therapy (PDT) is a medical treatment involving the use of a photosensitizing agent which is exposed to a specific wavelength of light to create oxygen radicals, resulting in the destruction of cancer cells, bacteria, viruses or fungi. A PDT system consists of three principal components: a photosensitizing agent, a light source (typically a laser) and a light delivery means (typically optical fiber based). 
         [0004]    PDT involves the use of a photosensitizing agent that is relatively selectively concentrated in cancer cells or microbiological pathogen sites. Depending on the type of photosensistizer, it may be injected intravenously, ingested orally or applied topically. After application of the photosensitizing agent it is selectively retained by diseased tissue so that after a period of time, determined by the kinetics of the compound&#39;s distribution, there is more photosensitizing agent absorbed by the diseased tissue than in normal tissue. The photosensitizing agent is then activated by exposure to a specific wavelength of light matching the absorption rates. This results in tissue necrosis via several mechanisms including oxygen radical production as well as vascular shutdown to the diseased tissue. Because there is less photosensitizer in the adjacent normal tissue, only the diseased tissue necroses and the normal tissue is preserved when the correct light dose rate for that tissue is administered. The advantage of PDT over conventional treatment such as surgery, radiation and chemotherapy is its relatively selective destruction of diseased tissue with normal tissue preservation. 
         [0005]    The light distribution properties of the light delivery device can have direct impact on the effectiveness of the light application and thus the efficacy of the PDT treatment. The challenge of the light delivery devices is to ensure the light distribution is equal along the entire length of the light emitting section of the device. Several types of distributing devices have been developed in attempts to more evenly and safely distribute the light and energy radiating from the device used to deliver the laser energy. One type of diffusing device involves a fiber optic microlens which is able to transfer a divergent light beam to a limited area tissue area. A light diffusion device, as disclosed in U.S. Pat. No. 4,660,925 to McCaughen, Jr. consists of a fiber cylindrical diffuser which emits a cylindrical scattering pattern of light output with respect to the cylindrical axis of the optical fiber, using a spaced series of rings of varying intensity light. Yet another diffusion device as disclosed in U.S. Pat. No. 4,693,556 to McCaughen, Jr. consists of a fiber optic spherical diffuser or “light bulb” which produces a spherical scattering light field. Each of these diffusing devices produces a light field of varying intensity over the area of emitted light from the optical fiber which may result in an uneven activation of the photosensitizer over the treatment area. In still another device, as disclosed in U.S. Pat. Nos. 5,536,265 and 5,695,583 to van den Bergh et al., the cladding is removed from a plastic optical fiber and replaced by a scattering medium which may or may not be roughened, resulting in a light emission area. This device is problematic in that the distal area of the light emitting area is less intense than the more proximal areas of the light emitting area of the device. What is clearly needed, then, is an improved optical fiber that is able to more evenly deliver light energy over a wider surface area. 
         [0006]    It is understood that the present invention as described and claimed herein can be used for many additional purposes, therefore the invention is within the scope of other fields and uses and not so limited. 
       SUMMARY 
       [0007]    In one aspect, the present invention comprises a light diffusing device having an optical fiber defining a longitudinal dimension, a lateral dimension and a distal end. A core fiber is at least partially covered by cladding and a light emitting section is formed by selectively removing cladding such that a progressively distally increasing surface area of core fiber is exposed, resulting in an even distribution of light emitted from the light emitting section. The light emitting section further defines a distal end and a proximal end. 
         [0008]    In another aspect, the present invention comprises a light diffusing device having an optical fiber defining a length, a diameter, a proximal end, a distal end and a core fiber at least partially covered by cladding. A light emitting section is formed by removing the cladding covering the light emitting section and selectively removing core fiber thereby progressively distally increasing the surface area of exposed core fiber, resulting in an even distribution of light emitted from the light emitting section. The light emitting section further defines a distal end and a proximal end. 
         [0009]    In a further aspect, the present invention comprises a light diffusing device having an optical fiber defining a length, a diameter, a proximal end and a distal end and a core fiber at least partially covered by cladding wherein a light emitting section is formed by selectively removing cladding to form at least a single light port such that a progressively distally increasing surface area of core fiber is exposed, resulting in an even distribution of light emitted from the light emitting section. The light emitting section further defines a distal end and a proximal end. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  shows the distal end of an embodiment of the light diffusing device of the present invention having a plurality of similarly sized open areas through the cladding distally progressively closer in proximity to each other. 
           [0011]      FIG. 1A  is a plan view of the light diffusing device shown in  FIG. 1 . 
           [0012]      FIG. 1B  is a lateral cross section taken through the lines  1 B- 1 B as shown in  FIG. 1 . 
           [0013]      FIG. 2  shows the distal end of an embodiment of the light diffusing device of the present invention having a plurality of open areas through the cladding distally increasing in size. 
           [0014]      FIG. 2A  is a plan view of the light diffusing device shown in  FIG. 2 . 
           [0015]      FIG. 2B  is a lateral cross section taken through the lines  2 B- 2 B as shown in  FIG. 2 . 
           [0016]      FIG. 3  shows the distal end of an embodiment of the light diffusing device of the present invention having a plurality of similarly sized open areas through the cladding distally increasing in depth into the core fiber. 
           [0017]      FIG. 3A  is a plan view of the light diffusing device shown in  FIG. 3 . 
           [0018]      FIG. 3B  is a lateral cross section taken through the lines  3 B- 3 B as shown in  FIG. 3 , showing openings through the cladding and into the core fiber having a relatively shallow depth. 
           [0019]      FIG. 3C  is a lateral cross section taken through the lines  3 C- 3 C as shown in  FIG. 3 , showing openings through the cladding and into the core fiber having a relatively intermediate depth. 
           [0020]      FIG. 3D  is a lateral cross section taken through the lines  3 D- 3 D as shown in  FIG. 3 , showing openings through the cladding and into the core fiber having a relatively deep depth. 
           [0021]      FIG. 4A  is a top view of the distal end of a light diffusing device of the present invention having a continuous opening through the cladding and extending progressively distally deeper into the core fiber. 
           [0022]      FIG. 4B  is a side view of the distal end of the light diffusing device shown in  FIG. 4A  using phantom lines to show the continuous opening extending progressively distally deeper into the core fiber. 
           [0023]      FIG. 4C  is a plan view of the light diffusing device shown in  FIG. 4 . 
           [0024]      FIG. 4D  is a lateral cross section taken through the lines  4 D- 4 D as shown in  FIGS. 4A-4B , showing the opening through the cladding and into the core fiber having a relatively shallow depth. 
           [0025]      FIG. 4E  is a lateral cross section taken through the lines  4 E- 4 E as shown in  FIGS. 4A-4B , showing the opening through the cladding and into the core fiber having a relatively intermediate depth. 
           [0026]      FIG. 4F  is a lateral cross section taken through the lines  4 F- 4 F as shown in  FIGS. 4A-4B , showing the opening through the cladding and into the core fiber having a relatively deep depth. 
           [0027]      FIG. 5  shows the distal end of a light diffusing device of the present invention having a continuous opening extending distally wider through the cladding. 
           [0028]      FIG. 5A  is a plan view of the light diffusing device shown in  FIG. 5 . 
           [0029]      FIG. 5B  is a lateral cross section taken through the lines  5 B- 5 B as shown in  FIG. 5 , showing the opening through the cladding and into the core fiber having a relatively narrow width. 
           [0030]      FIG. 5C  is a lateral cross section taken through the lines  5 C- 5 C as shown in  FIG. 5 , showing the opening through the cladding and into the core fiber having a relatively intermediate width. 
           [0031]      FIG. 5D  is a lateral cross section taken through the lines  5 D- 5 D as shown in  FIG. 5 , showing the opening through the cladding and into the core fiber having a relatively wide width. 
           [0032]      FIG. 6  shows the distal end of an embodiment of the light diffusing device of the present invention having an exposed core fiber at the distal end with a plurality of similarly sized removed core fiber sections distally progressively closer in proximity to each other. 
           [0033]      FIG. 6A  is a plan view of the light diffusing device shown in  FIG. 6 . 
           [0034]      FIG. 6B  is a lateral cross section taken through the lines  6 B- 6 B as shown in  FIG. 6 . 
           [0035]      FIG. 7  shows the distal end of an embodiment of the light diffusing device of the present invention having an exposed core fiber at the distal end with a plurality of removed core fiber sections distally increasing in size. 
           [0036]      FIG. 7A  is a plan view of the light diffusing device shown in  FIG. 7 . 
           [0037]      FIG. 7B  is a lateral cross section taken through the lines  7 B- 7 B as shown in  FIG. 7 . 
           [0038]      FIG. 8  shows the distal end of an embodiment of the light diffusing device of the present invention having an exposed core fiber at the distal end with a plurality of similarly sized removed core fiber sections distally increasing in depth into the core fiber. 
           [0039]      FIG. 8A  is a plan view of the light diffusing device shown in  FIG. 8 . 
           [0040]      FIG. 8B  is a lateral cross section taken through the lines  8 B- 3 B as shown in  FIG. 8 , showing removed core fiber sections and into the core fiber having a relatively shallow depth. 
           [0041]      FIG. 8C  is a lateral cross section taken through the lines  8 C- 8 C as shown in  FIG. 8 , showing removed core fiber sections and into the core fiber having a relatively intermediate depth. 
           [0042]      FIG. 8D  is a lateral cross section taken through the lines  8 D- 8 D as shown in  FIG. 8 , showing removed core fiber sections and into the core fiber having a relatively deep depth. 
           [0043]      FIG. 9A  is a top view of the distal end of a light diffusing device of the present invention having an exposed core fiber at the distal end with a continuous removed core fiber section extending progressively distally deeper into the core fiber. 
           [0044]      FIG. 9B  is a side view of the distal end of the light diffusing device shown in  FIG. 9A  using phantom lines to show the continuous opening extending progressively distally deeper into the core fiber. 
           [0045]      FIG. 9C  is a plan view of the light diffusing device shown in  FIG. 9 . 
           [0046]      FIG. 9D  is a lateral cross section taken through the lines  9 D- 9 D as shown in  FIG. 9 , showing the removed core fiber section extending into the core fiber to a relatively shallow depth. 
           [0047]      FIG. 9E  is a lateral cross section taken through the lines  9 E- 9 E as shown in  FIG. 9 , showing the removed core fiber section extending into the core fiber to a relatively intermediate depth. 
           [0048]      FIG. 9F  is a lateral cross section taken through the lines  9 F- 9 F as shown in  FIG. 9 , showing the removed core fiber section extending into the core fiber to a relatively deep depth. 
           [0049]      FIG. 10  shows the distal end of a light diffusing device of the present invention having an exposed core fiber at the distal end with a continuous removed core fiber section extending distally wider across the core fiber. 
           [0050]      FIG. 10A  is a plan view of the light diffusing device shown in  FIG. 10 . 
           [0051]      FIG. 10B  is a lateral cross section taken through the lines  10 B- 10 B as shown in  FIG. 10 , showing the removed core fiber section extending into the core fiber to a relatively narrow width. 
           [0052]      FIG. 10C  is a lateral cross section taken through the lines  10 C- 10 C as shown in  FIG. 10 , showing the removed core fiber section extending into the core fiber to a relatively intermediate width. 
           [0053]      FIG. 10D  is a lateral cross section taken through the lines  10 D- 10 D as shown in  FIG. 10 , showing the removed core fiber section extending into the core fiber to a relatively wide width. 
           [0054]      FIG. 11  shows the distal end of an embodiment of the light diffusing device of the present invention having an exposed core fiber at the distal end with the exposed core fiber progressively distally rougher. 
           [0055]      FIG. 11A  is a plan view of the light diffusing device shown in  FIG. 11 . 
           [0056]      FIG. 12  shows the distal end of an embodiment of the light diffusing device of the present invention having a plurality of similarly sized open areas through the cladding distally progressively closer in proximity to each other. A piercing tip is attached to the distal end of the device. 
           [0057]      FIG. 12A  is a plan view of the light diffusing device shown in  FIG. 12 . 
           [0058]      FIG. 12B  is a lateral cross section taken through the lines  12 B- 12 B as shown in  FIG. 12 . 
           [0059]      FIG. 13A  is a top view of the distal end of a light diffusing device of the present invention having a continuous opening through the cladding and extending progressively distally deeper into the core fiber. A piercing tip is attached to the distal end of the device. Fluorescent material is embedded in the sheathing. 
           [0060]      FIG. 13B  is a side view of the distal end of the light diffusing device shown in  FIG. 13A  using phantom lines to show the continuous opening extending progressively distally deeper into the core fiber. 
           [0061]      FIG. 13C  is a plan view of the light diffusing device shown in  FIGS. 13A-13B . 
           [0062]      FIG. 13D  is a lateral cross section taken through the lines  13 D- 13 D as shown in  FIGS. 13A-13B , showing the opening through the cladding and into the core fiber having a relatively shallow depth. 
           [0063]      FIG. 13E  is a lateral cross section taken through the lines  13 E- 13 E as shown in  FIGS. 13A-13B , showing the opening through the cladding and into the core fiber having a relatively intermediate depth. 
           [0064]      FIG. 13F  is a lateral cross section taken through the lines  13 F- 13 FD as shown in  FIGS. 13A-13B , showing the opening through the cladding and into the core fiber having a relatively deep depth. 
           [0065]      FIG. 14  shows the distal end of a light diffusing device of the present invention having a continuous opening extending distally wider through the cladding. The device is sheathed and a piercing tip is attached to the distal end of the device. 
           [0066]      FIG. 14A  is a plan view of the light diffusing device shown in  FIG. 14 . 
           [0067]      FIG. 14B  is a lateral cross section taken through the lines  14 B- 14 B as shown in  FIG. 14 , showing the opening through the sheathing and cladding and into the core fiber having a relatively narrow width. 
           [0068]      FIG. 14C  is a lateral cross section taken through the lines  14 C- 14 C as shown in  FIG. 14 , showing the opening through the sheathing and cladding and into the core fiber having a relatively intermediate width. 
           [0069]      FIG. 14D  is a lateral cross section taken through the lines  14 D- 14 D as shown in  FIG. 14 , showing the opening through the sheathing and cladding and into the core fiber having a relatively wide width. 
           [0070]      FIG. 15  shows the distal end of an embodiment of the light diffusing device of the present invention having a plurality of open areas through the cladding distally increasing in size. The device is sheathed and a piercing tip is attached to the distal end of the device. Fluorescent material is embedded in the sheathing. 
           [0071]      FIG. 15A  is a plan view of the light diffusing device shown in  FIG. 15 . 
           [0072]      FIG. 15B  is a lateral cross section taken through the lines  15 B- 15 B as shown in  FIG. 15 . 
           [0073]      FIG. 16  shows the distal end of an embodiment of the light diffusing device of the present invention having a plurality of similarly sized open areas through the cladding distally increasing in depth into the core fiber. The device is sheathed and the sheathing is configured on the distal end to be able to pierce tissue. Fluorescent material is embedded in the sheathing. 
           [0074]      FIG. 16A  is a plan view of the light diffusing device shown in  FIG. 16 . 
           [0075]      FIG. 16B  is a lateral cross section taken through the lines  16 B- 16 B as shown in  FIG. 16 , showing openings through the cladding and into the core fiber having a relatively shallow depth. 
           [0076]      FIG. 16C  is a lateral cross section taken through the lines  16 C- 16 C as shown in  FIG. 16 , showing openings through the cladding and into the core fiber having a relatively intermediate depth. 
           [0077]      FIG. 16D  is a lateral cross section taken through the lines  16 D- 16 D as shown in  FIG. 16 , showing openings through the cladding and into the core fiber having a relatively deep depth. 
           [0078]      FIG. 17  shows the distal end of an embodiment of the light diffusing device of the present invention having cladding covering the light diffusing section with the exposed cladding progressively distally rougher. 
           [0079]      FIG. 17A  is a plan view of the light diffusing device shown in  FIG. 17 . 
           [0080]      FIG. 17B  is a lateral cross section taken through the lines  17 B-  1   7 B as shown in  FIG. 17 , showing openings through the cladding core fiber. 
       
    
    
     DETAILED DESCRIPTION 
       [0081]    The particulars shown herein are by way of example and for purposes of illustrative discussion of the invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for the fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. 
       Nomenclature 
       [0000]    
       
           10  Optical Fiber 
           100  Light Diffusing Device 
           102  Light Emitting Section 
           102   a  Distal End (Light Emitting Section) 
           102   b  Proximal End (Light Emitting Section) 
           104  Light Port 
           105  Proximal End 
           106  Distal End 
           108  Cladding 
           110  Core Fiber 
           112  Connector 
           114  End Piece 
           200  Light Diffusing Device 
           202  Light Emitting Section 
           202   a  Distal End (Light Emitting Section) 
           202   b  Proximal End (Light Emitting Section) 
           204  Light Port 
           205  Proximal End 
           206  Distal End 
           208  Cladding 
           210  Core Fiber 
           212  Connector 
           214  End Piece 
           300  Light Diffusing Device 
           302  Light Emitting Section 
           302   a  Distal End (Light Emitting Section) 
           302   b  Proximal End (Light Emitting Section) 
           304  Light Port 
           305  Proximal End 
           306  Distal End 
           308  Cladding 
           310  Core Fiber 
           312  Connector 
           314  End Piece 
           400  Light Diffusing Device 
           402  Light Emitting Section 
           402   a  Distal End (Light Emitting Section) 
           402   b  Proximal End (Light Emitting Section) 
           404  Light Port 
           405  Proximal End 
           406  Distal End 
           408  Cladding 
           410  Core Fiber 
           412  Connector 
           414  End Piece 
           500  Light Diffusing Device 
           502  Light Emitting Section 
           502   a  Distal End (Light Emitting Section) 
           502   b  Proximal End (Light Emitting Section) 
           504  Light Port 
           505  Proximal End 
           506  Distal End 
           508  Cladding 
           510  Core Fiber 
           512  Connector 
           514  End Piece 
           600  Light Diffusing Device 
           602  Light Emitting Section 
           602   a  Distal End (Light Emitting Section) 
           602   b  Proximal End (Light Emitting Section) 
           604  Removed Core Fiber Section 
           605  Proximal End 
           606  Distal End 
           608  Cladding 
           610  Core Fiber 
           612  Connector 
           614  End Piece 
           700  Light Diffusing Device 
           702  Light Emitting Section 
           702   a  Distal End (Light Emitting Section) 
           702   b  Proximal End (Light Emitting Section) 
           704  Removed Core Fiber Section 
           705  Proximal End 
           706  Distal End 
           708  Cladding 
           710  Core Fiber 
           712  Connector 
           714  Piercing Tip 
           800  Light Diffusing Device 
           802  Light Emitting Section 
           802   a  Distal End (Light Emitting Section) 
           802   b  Proximal End (Light Emitting Section) 
           804  Removed Core Fiber Section 
           805  Proximal End 
           806  Distal End 
           808  Cladding 
           810  Core Fiber 
           812  Connector 
           814  End Piece 
           900  Light Diffusing device 
           902  Light Emitting Section 
           902   a  Distal End (Light Emitting Section) 
           902   b  Proximal End (Light Emitting Section) 
           904  Removed Core Fiber Section 
           905  Proximal End 
           906  Distal End 
           908  Cladding 
           910  Core Fiber 
           912  Connector 
           914  End Piece 
           1000  Light Diffusing Device 
           1002  Light Emitting Section 
           1002   a  Distal End (Light Emitting Section) 
           1002   b  Proximal End (Light Emitting Section) 
           1004  Removed Core Fiber Section 
           1005  Proximal End 
           1006  Distal End 
           1008  Cladding 
           1010  Core Fiber 
           1012  Connector 
           1014  End Piece 
           1100  Light Diffusing Device 
           1102  Light Emitting Section 
           1102   a  Distal End (Light Emitting Section) 
           1102   b  Proximal End (Light Emitting Section) 
           1104   a  Rougher Section of Core Fiber 
           1104   b  Smoother Section of Core Fiber 
           1105  Proximal End 
           1106  Distal End 
           1108  Cladding 
           1110  Core Fiber 
           1112  Connector 
           1114  End Piece 
           1200  Light Diffusing device 
           1202  Light Emitting Section 
           1202   a  Distal End (Light Emitting Section) 
           1202   b  Proximal End (Light Emitting Section) 
           1204  Light Port 
           1205  Proximal End 
           1206  Distal End 
           1208  Cladding 
           1210  Core Fiber 
           1212  Connector 
           1214  Piercing Tip 
           1300  Light Diffusing device 
           1302  Light Emitting Section 
           1302   a  Distal End (Light Emitting Section) 
           1302   b  Proximal End (Light Emitting Section) 
           1304  Light Port 
           1305  Proximal End 
           1306  Distal End 
           1308  Cladding 
           1310  Core Fiber 
           1312  Connector 
           1314  Piercing Tip 
           1316  Fluorescent Material 
           1400  Light Diffusing device 
           1402  Light Emitting Section 
           1402   a  Distal End (Light Emitting Section) 
           1402   b  Proximal End (Light Emitting Section) 
           1404  Light Port 
           1405  Proximal End 
           1406  Distal End 
           1408  Cladding 
           1410  Core Fiber 
           1412  Connector 
           1414  Piercing Tip 
           1418  Sheathing 
           1500  Light Diffusing device 
           1502  Light Emitting Section 
           1502   a  Distal End (Light Emitting Section) 
           1502   b  Proximal End (Light Emitting Section) 
           1504  Light Port 
           1505  Proximal End 
           1506  Distal End 
           1508  Cladding 
           1510  Core Fiber 
           1512  Connector 
           1514  Piercing Tip 
           1516  Fluorescent Material 
           1518  Sheathing 
           1600  Light Diffusing device 
           1602  Light Emitting Section 
           1602   a  Distal End (Light Emitting Section) 
           1602   b  Proximal End (Light Emitting Section) 
           1604  Light Port 
           1605  Proximal End 
           1606  Distal End 
           1608  Cladding 
           1610  Core Fiber 
           1612  Connector 
           1614  Piercing Distal End 
           1616  Fluorescent Material 
           1618  Sheathing 
           1700  Light Diffusing Device 
           1702  Light Emitting Section 
           1702   a  Distal End (Light Emitting Section) 
           1702   b  Proximal End (Light Emitting Section) 
           1704   a  Rougher Section of Light Emitting Section 
           1704   b  Smoother Section of Light Emitting Section 
           1705  Proximal End 
           1706  Distal End 
           1708  Cladding 
           1710  Core Fiber 
           1712  Connector 
           1714  End Piece 
       
     
       Definitions 
       [0278]    “Distal” means further from the point controlled by the operator (e.g., physician or technician) of a device. 
         [0279]    “Opaque” means absorbing light energy in a particular wavelength range. 
         [0280]    “Proximal” means closer to the point controlled by the operator (e.g., physician or technician) of a device. 
       Construction 
       [0281]      FIG. 1  shows the light emitting section  102  of an embodiment of a light diffusing device  100  of the present invention.  FIG. 1A  shows the entire light diffusing device  100 , including a connector  112  attached to the proximal end  105  allowing the light diffusing device  100  to be connected to a light source (not shown). As best shown in  FIG. 1B  the light diffusing device  100  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  110  made of PMMA (acrylic) surrounded by cladding  108  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. The core fiber  110  and cladding  108  have different indexes of refraction, which enables light entering the light diffusing device  100  at the connector  112  to be transmitted along the length of the light diffusing device  100  and therefore transmitted to a more distal location. The light diffusing device  100  defines a distal end  106  to which is attached an opaque end piece  114 , preventing the escape of the transmitted light energy from an otherwise open distal end (not shown) of the core fiber  110 . In one embodiment, the end piece  114  can be made of stainless steel. Using appropriate medical grade adhesives, the end piece  114  is attached to the distal end  106  of the optical fiber  10  after the distal end  106  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive or erosive methods. In another embodiment (not shown) the end piece  114  may be omitted and replaced by other light blocking mechanisms including opaque epoxy or plastic materials. In an alternative embodiment (not shown) the light diffusing device  100  may be encased in a transparent protective sheath (not shown) which provides an additional degree of integrity as well as smoothness. 
         [0282]    The light emitting section  102  is defined by a plurality of light ports  104  which extend through the cladding  108  exposing the core fiber  110 , thereby allowing the transmitted light energy to be emitted from the light diffusing device  100 . As best shown in  FIG. 1 , the light emitting section  102  is characterized by the light ports  104  having a similar surface area and progressively denser in distribution (greater in number) as the distal end  102   a  is reached. As shown in  FIG. 1B  the light ports  104  are round shaped and spacing may vary between 0.022 inches to 0.040 inches. Restated, a denser distribution of similarly sized light ports  104  at the distal end  102   a  results in a lesser exposed core fiber  110  surface area at the proximal end  102   b  of the light emitting section  102  and a greater exposed core fiber  110  surface area at the distal end  102   a  of the light emitting section  102 , allowing a greater quantity of light to be available at the distal end  102   a  of the light emitting section  102 . The reason for this is that if the distribution of light ports  104  was even (not shown), more light would be emitted from the more proximally located light ports  104 , leaving less light available to be emitted from the more distally located light ports  104 . The result of evenly distributed light ports  104  (not shown) would be a device (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  100  shown in  FIGS. 1-1B  thus evenly emits the transmitted light energy along the length of the light emitting section  102 , allowing safer and more precise photodynamic therapy. 
         [0283]      FIG. 2  shows the light emitting section  202  of an embodiment of a light diffusing device  200  of the present invention.  FIG. 2A  shows the entire light diffusing device  200 , including a connector  212  attached to the proximal end  205  allowing the light diffusing device  200  to be connected to a light source (not shown). As best shown in  FIG. 2B  the light diffusing device  200  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  210  made of PMMA (acrylic) surrounded by cladding  208  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. The core fiber  210  and cladding  208  have different indexes of refraction, which enables light entering the light diffusing device  200  at a proximal location to be transmitted along the length of the light diffusing device  200  and thereby transmitted to a more distal location. The light diffusing device  200  defines a distal end  206  which comprises an opaque end piece  214 , preventing the escape of the transmitted light energy from the core fiber  210 . In one embodiment the end piece  214  is made of stainless steel. In this embodiment a section of fluorescent material  216  is placed between the end piece  214  and the distal end  206  of the optical fiber  10 . The fluorescent material  216  can be made of chromium crystal, however, this is not intended to be limiting as other materials including alexandrite, sapphire and others would also work. Using appropriate medical grade adhesives, the fluorescent material  216  is attached to the distal end  206  of the optical fiber  10  after the distal end  206  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive or erosive methods. Following attachment of the fluorescent material  216  to the optical fiber  10 , the opaque end piece  214  is attached to the distal end (unnumbered) of the fluorescent material  216  using appropriate medical grade adhesives. The end piece  214  prevents the escape of light energy through the distal end  206 . The fluorescent material  216  emits a signal when illuminated by light energy having a wavelength at least at an excitation wavelength and above and thus functions as a fluorescence feedback indicator. In this configuration, when the laser light source (not shown) is energized, fluorescence occurs at the distal end  206  and is detected at the light source console (not shown) to verify the light diffusing device  200  is valid and functioning properly. In another embodiment (not shown) the end piece  214  may be omitted and replaced by other light blocking mechanisms including opaque epoxy or plastic materials. In an alternative embodiment (not shown) the light diffusing device  200  may be encased in a transparent protective sheath (not shown) which provides an additional degree of integrity as well as smoothness. 
         [0284]    The light emitting section  202  is defined by a plurality of light ports  204  which extend through the cladding  208  exposing the core fiber  210  allowing the transmitted light energy to be emitted from the light diffusing device  200 . As best shown in  FIG. 2 , the light emitting section  202  is characterized by the light ports  204  progressively defining a greater surface area as the distal end  206  is reached. The light ports  204  are conically shaped and spacing may vary in diameter between 0.003 inches to 0.006 inches. Restated, progressively greater sized light ports  204  toward the distal end  202   a  result in a lesser exposed core fiber  210  surface area at the proximal end  202   b  of the light emitting section  202  and a greater exposed core fiber  210  surface area at the distal end  202   a  of the light emitting section  202 , allowing a greater quantity of light to be available at the distal end  206  of the light emitting section  202 . The reason for this is that if the surface area of the light ports  204  was consistent (not shown), more light would be emitted from the more proximally located light ports  204 , leaving less light available to be emitted from the more distally located light ports  204 . The result of similarly sized light ports  204  (not shown) would be a device (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  200  shown in  FIGS. 2-2B  thus evenly emits the transmitted light energy along the length of the light emitting section  202 , allowing safer and more precise photodynamic therapy. 
         [0285]      FIG. 3  shows the light emitting section  302  of an embodiment of a light diffusing device  300  of the present invention.  FIG. 3A  shows the entire light diffusing device  300 , including a connector  312  attached to the proximal end  305  allowing the light diffusing device  300  to be connected to a light source (not shown). As best shown in  FIGS. 3B ,  3 C,  3 D the light diffusing device  300  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  310  made of PMMA (acrylic) surrounded by cladding  308  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. The core fiber  310  and cladding  308  have different indexes of refraction, which enables light entering the light diffusing device  300  at the connector  312  to be transmitted along the length of the light diffusing device  300  and thereby transmitted to a more distal location. The light diffusing device  300  defines a distal end  306  to which is attached an opaque end piece  314 , preventing the escape of the transmitted light energy from an open distal end (not shown) of the core fiber  310 . The end piece  314  can be made of stainless steel. Using appropriate medical grade adhesives, the end piece  314  is attached to the distal end  306  of the light diffusing device  300  after the distal end  306  of the optical fiber  10  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive or erosive methods. In another embodiment (not shown) the end piece  314  may be omitted and replaced by other light blocking mechanisms including opaque epoxy or plastic materials. In an alternative embodiment (not shown) the light diffusing device  300  may be encased in a transparent protective sheath (not shown) which provides an additional degree of integrity as well as smoothness. 
         [0286]    The light emitting section  302  is defined by a plurality of light ports  304  which extend through the cladding  308  into the core fiber  300  allowing the transmitted light to be emitted from the light diffusing device  300 . As best shown in  FIGS. 3B ,  3 C,  3 D, the light emitting section  302  is characterized by the light ports  304  having a similar surface area and progressively deeper into the core fiber  310  as the distal end  302   a  is reached, thus exposing a greater amount of core fiber  310 . The light ports  304  are conically shaped and the depth may vary between 0.004 inches to 0.008 inches. Restated, progressively deeper, similarly sized light ports  304  toward the distal end  302   a  result in a lesser exposed core fiber  310  surface area at the proximal end  302   b  of the light emitting section  302  and a greater exposed core fiber  310  surface area at the distal end  302   a  of the light emitting section  302 , allowing a greater quantity of light to be available at the distal end  302   a  of the light emitting section  302 . The reason for this is that if the size and depth of light ports  304  was consistent (not shown), more light would be emitted from the more proximally located light ports  304 , leaving less light available to be emitted from the more distally located light ports  304 . The result of similarly sized and depth light ports  304  (not shown) would be a device (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  300  shown in  FIG. 3  thus evenly emits the transmitted light energy along the length of the light emitting section  302 , allowing safer and more precise photodynamic therapy. 
         [0287]      FIG. 4A  shows a top view of the light emitting section  402  of an embodiment of the light diffusing device  400  of the present invention. A side view is shown in  FIG. 4B , with phantom lines indicating the location and depth of the light port  404 .  FIG. 4C  shows the entire light diffusing device  400 , including a connector  412  attached to the proximal end  405  allowing the light diffusing device  400  to be connected to a light source (not shown). As best shown in  FIGS. 4D ,  4 E,  4 F the light diffusing device  400  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  410  made of PMMA (acrylic) surrounded by cladding  408  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. The core fiber  410  and cladding  408  have different indexes of refraction, which enables light entering the light diffusing device  400  at the connector  412  to be transmitted along the length of the light diffusing device  400  and thereby transmitted to a more distal location. The light diffusing device  400  defines a distal end  406  which comprises an opaque end piece  414 , preventing the escape of the transmitted light energy from an otherwise open distal end (not shown) of the core fiber  410 . In one embodiment, the end piece  414  is made of stainless steel. Using appropriate medical grade adhesives, the end piece  414  is attached to the distal end  406  of the optical fiber  10  after the distal end  406  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive methods. In another embodiment (not shown) the end piece  414  may be omitted and replaced by other light blocking mechanisms including opaque epoxy or plastic materials. In an alternative embodiment (not shown) the light diffusing device  400  may be encased in a transparent protective sheath (not shown) which provides an additional degree of integrity as well as smoothness. 
         [0288]    The light emitting section  402  is defined by an extended light port  404  which is cut through the cladding  408  into the core fiber  400  allowing the transmitted light to be emitted from the light diffusing device  400 . While a single extended light port  404  is shown in  FIGS. 4-4F , this is for purposes of illustration only and the invention could also include multiple extended light ports  404  (not shown). As best shown in  FIGS. 4D ,  4 E,  4 F, the light emitting section  402  is characterized by the light port  404  extending progressively deeper into the core fiber  410  as the distal end  402   a  is reached. Restated, the progressively deeper light port  404  toward the distal end  402   a  results in a lesser exposed core fiber  410  surface area at the proximal end  402   b  of the light emitting section  402  and a greater exposed core fiber  410  surface area at the distal end  402   a  of the light emitting section  402 , allowing a greater quantity of light to be available at the distal end (unnumbered) of the light emitting section  402 . The reason for this is that if the depth of the light port  404  was consistent (not shown), more light would be emitted from the proximal end of the light port  404 , leaving less light available to be emitted from the distal end of the light port  404 . The result of a uniform depth light port  404  (not shown) would be an optical fiber (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  400  shown in  FIG. 4  thus evenly emits the transmitted light energy along the length of the light emitting section  402 , allowing safer and more precise photodynamic therapy. 
         [0289]      FIG. 5  shows the light emitting section  502  of an embodiment of the light diffusing device  500  of the present invention.  FIG. 5A  shows the entire light diffusing device  500 , including a connector  512  attached to the proximal end  505  allowing the light diffusing device  500  to be connected to a light source (not shown). As best shown in  FIGS. 5B ,  5 C,  5 D the light diffusing device  500  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  510  made of PMMA (acrylic) surrounded by cladding  508  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. The core fiber  510  and cladding  508  have different indexes of refraction, which enables light entering the light diffusing device  500  at the connector  512  to be transmitted along the length of the light diffusing device  500  and thereby transmitted to a more distal location. The light diffusing device  500  defines a distal end  506  to which is attached an opaque end piece  514 , preventing the escape of the transmitted light energy from an open distal end (not shown) of the core fiber  510 . In one embodiment, the end piece  514  is made of stainless steel. Using appropriate medical grade adhesives, the end piece  514  is attached to the distal end  506  of the optical fiber  10  after the distal end  506  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive or erosive methods. In another embodiment (not shown) the end piece  514  may be omitted and replaced by other light blocking mechanisms including opaque epoxy or plastic materials. In an alternative embodiment (not shown) the light diffusing device  500  may be encased in a transparent protective sheath (not shown) which provides an additional degree of integrity as well as smoothness. 
         [0290]    The light emitting section  502  is defined by an extended light port  504  which is cut through the cladding  508  exposing the core fiber  500  allowing the transmitted light to be emitted from the light diffusing device  500 . While a single extended light port  504  is shown in  FIGS. 5-5D , this is for purposes of illustration only and the invention could also include multiple extended light ports  504  (not shown). As best shown in  FIGS. 5B ,  5 C,  5 D, the light emitting section  502  is characterized by the light port  504  extending progressively wider through the cladding  508  as the distal end is reached. Restated, the progressively wider light port  504  toward the distal end results in a lesser exposed core fiber  510  surface area at the proximal end  502   b  of the light emitting section  502  and a greater exposed core fiber  510  surface area at the distal end  502   a  of the light emitting section  502 , allowing a greater quantity of light to be available at the distal end  502   a  of the light emitting section  502 . The reason for this is that if the width of the light port  504  was consistent (not shown), more light would be emitted from the proximal end  502   b  of the light port  504 , leaving less light available to be emitted from the distal end  502   a  of the light port  504 . The result of a uniform width light port  504  (not shown) would be an optical fiber (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  500  shown in  FIG. 5  thus evenly emits the transmitted light energy along the length of the light emitting section  502 , allowing safer and more precise photodynamic therapy. 
         [0291]      FIG. 6  shows the light emitting section  602  of an embodiment of a light diffusing device  600  of the present invention.  FIG. 6A  shows the entire light diffusing device  600 , including a connector  612  attached to the proximal end  605  allowing the light diffusing device  600  to be connected to a light source (not shown). As best shown in  FIG. 6B  the light diffusing device  600  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  610  made of PMMA (acrylic) surrounded by cladding  608  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. The core fiber  610  and cladding  608  have different indexes of refraction, which enables light entering the light diffusing device  600  at the connector  612  to be transmitted along the length of the light diffusing device  600  and therefore transmitted to a more distal location. The light diffusing device  600  defines a distal end  606  to which is attached an opaque end piece  614 , preventing the escape of the transmitted light energy from an open distal end (not shown) of the core fiber  610 . In one embodiment, the end piece  614  is made of stainless steel. Using appropriate medical grade adhesives, the end piece  614  is attached to the distal end  606  of the optical fiber  10  after the distal end  606  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive or erosive methods. In another embodiment (not shown) the end piece  614  may be omitted and replaced by other light blocking mechanisms including opaque epoxy or plastic materials. In an alternative embodiment (not shown) the light diffusing device  600  may be encased in a transparent protective sheath (not shown) which provides an additional degree of integrity as well as smoothness. 
         [0292]    In this embodiment the light diffusing device  600  has an exposed section of core fiber  610  which defines the light emitting section  602 . The light emitting section  602  is further defined by a plurality of removed core fiber sections  604  which extend into the core fiber  610  allowing additional transmitted light energy to be emitted from the light diffusing device  600  as a result of a greater exposed surface area of the core fiber  604 . As best shown in  FIG. 6 , the light emitting section  602  is characterized by the removed core fiber sections  604  having a similar surface area and progressively denser in distribution (greater in number) as the distal end  602   a  is reached. As shown in  FIG. 6B  the removed core fiber sections  604  are conical and spacing may vary between 0.022 inches to 0.040 inches. Restated, a denser distribution of similarly sized removed core fiber sections  604  at the distal end  602   a  results in a lesser exposed core fiber  610  surface area at the proximal end  602   b  of the light emitting section  602  and a greater exposed core fiber  610  surface area at the distal end  602   a  of the light emitting section  602 , allowing a greater quantity of light to be available at the distal end  602   a  of the light emitting section  602 . The reason for this is that if the distribution of removed core fiber sections  604  was even (not shown), more light would be emitted from the more proximally located removed core fiber sections  604 , leaving less light available to be emitted from the more distally located removed core fiber sections  604 . The result of evenly distributed removed core fiber sections  604  (not shown) would be an optical fiber (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  600  shown in  FIGS. 6-6B  thus evenly emits the transmitted light energy along the length of the light emitting section  602 , allowing safer and more precise photodynamic therapy. 
         [0293]      FIG. 7  shows the light emitting section  702  of an embodiment of a light diffusing device  700  of the present invention.  FIG. 7A  shows the entire light diffusing device  700 , including a connector  712  attached to the proximal end  705  allowing the light diffusing device  700  to be connected to a light source (not shown). As best shown in  FIG. 7B  the light diffusing device  700  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  710  made of PMMA (acrylic) surrounded by cladding  708  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. The core fiber  710  and cladding  708  have different indexes of refraction, which enables light entering the light diffusing device  700  at a proximal location to be transmitted along the length of the light diffusing device  700  and thereby transmitted to a more distal location. The light diffusing device  700  defines a distal end  706  to which is attached a piercing tip  714 , preventing the escape of the transmitted light energy from an open distal end (not shown) of the core fiber  710 . The piercing tip  714  also allows the device  700  to pierce or penetrate and thereby be implanted into tissue following the application of gentle force by the physician. In one embodiment, the piercing tip  714  is made of machined (sharpened) stainless steel and also functions to pierce or penetrate tissue as required for treatment. Using appropriate medical grade adhesives, the piercing tip  714  is attached to the distal end  706  of the optical fiber  10  after the distal end  706  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive or erosive methods. In an alternative embodiment (not shown) the light diffusing device  700  may be encased in a transparent protective sheath (not shown) which provides an additional degree of integrity as well as smoothness. 
         [0294]    In this embodiment the light diffusing device  700  has an exposed section of core fiber  710  which defines the light emitting section  702 . The light emitting section  702  is further defined by a plurality of removed core fiber sections  704  which extend into the core fiber  710  allowing additional transmitted light energy to be emitted from the light diffusing device  700 . As best shown in  FIG. 7 , the light emitting section  702  is characterized by the removed core fiber sections  704  being similarly numbered and progressively defining a greater surface area as the distal end  706  is reached. The removed core fiber sections  704  are conically shaped and spacing may vary in diameter between 0.003 inches to 0.006 inches. Restated, progressively greater sized removed core fiber sections  704  toward the distal end  702   a  result in a lesser exposed core fiber  710  surface area at the proximal end  702   b  of the light emitting section  702  and a greater exposed core fiber  710  surface area at the distal end  702   a  of the light emitting section  702 , allowing a greater quantity of light to be available at the distal end  706  of the light emitting section  702 . The reason for this is that if the exposed surface area of the removed core fiber sections  704  was consistent (not shown), more light would be emitted from the more proximally located removed core fiber sections  704 , leaving less light available to be emitted from the more distally located removed core fiber sections  704 . The result of similarly sized removed core fiber sections  704  (not shown) would be an optical fiber (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  700  shown in  FIGS. 7-7B  thus evenly emits the transmitted light energy along the length of the light emitting section  702 , allowing safer and more precise photodynamic therapy. 
         [0295]      FIG. 8  shows the light emitting section  802  of an embodiment of a light diffusing device  800  of the present invention.  FIG. 8A  shows the entire light diffusing device  800 , including a connector  812  attached to the proximal end  805  allowing the light diffusing device  800  to be connected to a light source (not shown). As best shown in  FIGS. 8C ,  8 D,  8 E the light diffusing device  800  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  810  made of PMMA (acrylic) surrounded by cladding  808  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. The core fiber  810  and cladding  808  have different indexes of refraction, which enables light entering the light diffusing device  800  at the connector  812  to be transmitted along the length of the light diffusing device  800  and thereby transmitted to a more distal location. In this embodiment a section of fluorescent material  816  is placed between the end piece  814  and the distal end  806  of the optical fiber  10 . The fluorescent material  816  can be made of chromium crystal, however, this is not intended to be limiting as other materials including alexandrite, sapphire and others would also work. Using appropriate medical grade adhesives, the fluorescent material  816  is attached to the distal end  806  of the optical fiber  10  after the distal end  806  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive or erosive methods. Following attachment of the fluorescent material  816  to the optical fiber  10 , the opaque end piece  814  is attached to the distal end (unnumbered) of the fluorescent material  816  using appropriate medical grade adhesives. The end piece  814  prevents the escape of light energy through the distal end  806 . The fluorescent material  816  emits a signal when illuminated by light energy having a wavelength at least at an excitation wavelength and above and thus functions as a fluorescence feedback indicator. In this configuration, when the laser light source (not shown) is energized fluorescence occurs at the distal end  806  and is detected at the light source console (not shown) to verify the light diffusing device  800  is valid and functioning properly. In another embodiment (not shown) the end piece  814  may be omitted and replaced by other light blocking mechanisms including opaque epoxy or plastic materials. In an alternative embodiment (not shown) the light diffusing device  800  may be encased in a transparent protective sheath (not shown) which provides an additional degree of integrity as well as smoothness. 
         [0296]    In this embodiment the light diffusing device  800  has an exposed section of core fiber  810  which defines the light emitting section  802 . The light emitting section  802  is further defined by a plurality of removed core fiber sections  804  which extend through into the core fiber  800  allowing the transmitted light to be emitted from the light diffusing device  810 . As best shown in  FIGS. 8C ,  8 D,  8 E the light emitting section  802  is characterized by the removed core fiber sections  804  having a similar surface area and extends progressively deeper into the core fiber  810  as the distal end  802   a  is reached. The removed core fiber sections  804  are conically shaped and the depth may vary between 0.004 inches to 0.008 inches. Restated, progressively deeper, similarly sized removed core fiber sections  804  toward the distal end  802   a  result in a lesser exposed core fiber  810  surface area at the proximal end  802   b  of the light emitting section  802  and a greater exposed core fiber  810  surface area at the distal end  802   a  of the light emitting section  802 , allowing a greater quantity of light to be available at the distal end  802   a  of the light emitting section  802 . The reason for this is that if the size and depth of removed core fiber sections  804  was consistent (not shown), more light would be emitted from the more proximally located removed core fiber sections  804 , leaving less light available to be emitted from the more distally located removed core fiber sections  804 . The result of similarly sized and depth removed core fiber sections  804  (not shown) would be a light diffusing device (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  800  shown in  FIG. 8  thus evenly emits the transmitted light energy along the length of the light emitting section  802 , allowing safer and more precise photodynamic therapy. 
         [0297]      FIG. 9A  shows a top view of the light emitting section  902  of an embodiment of the light diffusing device  900  of the present invention. A side view of the light emitting section  902  is shown in  FIG. 9B , with phantom lines indicating the depth of the continuous removed core fiber section  904 .  FIG. 9C  shows the entire light diffusing device  900 , including a connector  912  attached to the proximal end  905  allowing the light diffusing device  900  to be connected to a light source (not shown). As best shown in  FIGS. 9A ,  9 B the light diffusing device  900  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  910  made of PMMA (acrylic) surrounded by cladding  908  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. The core fiber  910  and cladding  908  have different indexes of refraction, which enables light entering the light diffusing device  900  at the connector  912  to be transmitted along the length of the light diffusing device  900  and thereby transmitted to a more distal location. The light diffusing device  900  defines a distal end  906  to which is attached an opaque end piece  914 , preventing the escape of the transmitted light energy from an otherwise open distal end (not shown) of the core fiber  910 . In one embodiment, the end piece  914  is made of stainless steel. Using appropriate medical grade adhesives, the end piece  914  is attached to the distal end  906  of the optical fiber  10  after the distal end  906  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive methods. In another embodiment (not shown) the end piece  914  may be omitted and replaced by other light blocking mechanisms including opaque epoxy or plastic materials. In an alternative embodiment (not shown) the light diffusing device  900  may be encased in a transparent protective sheath (not shown) which provides an additional degree of integrity as well as smoothness. 
         [0298]    In this embodiment the light diffusing device  900  has an exposed section of core fiber  910  which defines the light emitting section  902 . The light emitting section  902  is further defined by an extended removed core fiber section  904  which is cut into the core fiber  910  allowing an increased amount of transmitted light to be emitted from the light diffusing device  900 . While a single extended removed core fiber section  904  is shown in  FIGS. 9-9F , this is for purposes of illustration only and the invention could also include multiple extended removed core fiber sections  904  (not shown). As best shown in  FIGS. 9D ,  9 E,  9 F, the light emitting section  902  is characterized by the removed core fiber section  904  extending progressively deeper into the core fiber  910  as the distal end  902   a  is reached. Restated, the progressively deeper removed core fiber section  904  toward the distal end  902   a  results in a lesser exposed core fiber  910  surface area at the proximal end  902   b  of the light emitting section  902  and a greater exposed core fiber  910  surface area at the distal end  902   a  of the light emitting section  902 , allowing a greater quantity of light to be available at the distal end  902   a  of the light emitting section  902 . The reason for this is that if the depth of the removed core fiber section  904  was consistent (not shown), more light would be emitted from the proximal end of the removed core fiber section  904 , leaving less light available to be emitted from the distal end of the removed core fiber section  904 . The result of a uniform depth removed core fiber section  904  (not shown) would be alight diffusing device (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  900  shown in  FIG. 9  thus evenly emits the transmitted light energy along the length of the light emitting section  902 , allowing safer and more precise photodynamic therapy. 
         [0299]      FIG. 10  shows the light emitting section  1002  of an embodiment of the light diffusing device  1000  of the present invention.  FIG. 10A  shows the entire light diffusing device  1000 , including a connector  1012  attached to the proximal end  1005  allowing the light diffusing device  1000  to be connected to a light source (not shown). As best shown in  FIG. 10  the light diffusing device  1000  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  1010  made of PMMA (acrylic) surrounded by cladding  1008  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. The core fiber  1010  and cladding  1008  have different indexes of refraction, which enables light entering the light diffusing device  1000  at the connector  1012  to be transmitted along the length of the light diffusing device  1000  and thereby transmitted to a more distal location. The light diffusing device  1000  defines a distal end  1006  to which is attached an opaque end piece  1014 , preventing the escape of the transmitted light energy from an open distal end (not shown) of the core fiber  1010 . In one embodiment, the end piece  1014  is made of stainless steel. Using appropriate medical grade adhesives, the end piece  1014  is attached to the distal end  1006  of the optical fiber  10  after the distal end  1006  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive methods. In another embodiment (not shown) the end piece  1014  may be omitted and replaced by other light blocking mechanisms including opaque epoxy or plastic materials. In an alternative embodiment (not shown) the light diffusing device  1000  may be encased in a transparent protective sheath (not shown) which provides an additional degree of integrity as well as smoothness. 
         [0300]    In this embodiment the light diffusing device  1000  has an exposed section of core fiber  1010  which defines the light emitting section  1002 . The light emitting section  1002  is further defined by an extended removed core fiber section  1004  which is cut into the core fiber  1010  exposing a distally increased surface of core fiber  1010 , allowing an increased amount of transmitted light to be emitted from the light diffusing device  1000 . While a single extended removed core fiber section  1004  is shown in  FIGS. 10-10D , this is for purposes of illustration only and the invention could also include multiple extended removed core fiber sections  1004  (not shown). As best shown in  FIGS. 10 ,  10 A,  10 B,  10 C,  10 D, the light emitting section  1002  is characterized by the removed core fiber section  1004  extending progressively wider into the core fiber  1010  as the distal end  1002   a  is reached. Restated, the progressively wider removed core fiber section  1004  toward the distal end  1002   a  results in a lesser exposed core fiber  1010  surface area at the proximal end  1002   b  of the light emitting section  1002  and a greater exposed core fiber  1010  surface area at the distal end  1002   a  of the light emitting section  1002 , allowing a greater quantity of light to be available at the distal end  1002   a  of the light emitting section  1002 . The reason for this is that if the width and depth of the removed core fiber section  1004  was consistent (not shown), more light would be emitted from the proximal end  1002   b  of the removed core fiber section  1004 , leaving less light available to be emitted from the distal end of the removed core fiber section  1004 . The result of a uniform width/depth removed core fiber section  1004  (not shown) would be a light diffusing device (not shown) having uneven light distribution, with more intensity toward the proximal end  1002   b  and less toward the distal end  1002   a.  The embodiment of the light diffusing device  1000  shown in  FIG. 10  thus evenly emits the transmitted light energy along the length of the light emitting section  1002 , allowing safer and more precise photodynamic therapy. 
         [0301]      FIG. 11  shows the light emitting section  1102  of an embodiment of the light diffusing device  1100  of the present invention. A plan view of the light emitting section as shown in  FIG. 11A  shows the entire light diffusing device  1100 , including a connector  1112  attached to the proximal end  1105  allowing the light diffusing device  1100  to be connected to a light source (not shown). As best shown in  FIG. 9  the light diffusing device  1100  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  1110  made of PMMA (acrylic) surrounded by cladding  1108  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. The core fiber  1110  and cladding  1108  have different indexes of refraction, which enables light entering the light diffusing device  1100  at the connector  1112  to be transmitted along the length of the light diffusing device  1100  and thereby transmitted to a more distal location. The light diffusing device  1100  defines a distal end  1106  which comprises an opaque end piece  1114 , preventing the escape of the transmitted light energy from an open distal end (not shown) of the core fiber  1110 . In one embodiment, the end piece  1114  is made of stainless steel. Using appropriate medical grade adhesives, the end piece  1114  is attached to the distal end  1106  of the light diffusing device  1100  after the distal end  1106  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive methods. In another embodiment (not shown) the end piece  1114  may be omitted and replaced by other light blocking mechanisms including opaque epoxy or plastic materials. In an alternative embodiment (not shown) the light diffusing device  1100  may be encased in a transparent protective sheath (not shown) which provides an additional degree of integrity as well as smoothness. 
         [0302]    In this embodiment the light diffusing device  1100  has an exposed section of core fiber  1110  which defines the light emitting section  1102 . The light emitting section  1102  is further defined by progressively distally roughening the surface of the light emitting section  1102  allowing an increased amount of transmitted light to be emitted from the light diffusing device  1100 . As best shown in  FIG. 11  the light emitting section  1102  is characterized by the light emitting section  1102  having a relatively smooth area  1104   b  which becomes progressively rougher  1104   a  along the core fiber  1110  as the distal end  1102   a  is reached. Restated, the progressively rougher light emitting section  1102  toward the distal end  1102   a  results in a lesser exposed core fiber  1110  surface area at the proximal end  1102   b  of the light emitting section  1102  and a greater exposed core fiber  1110  surface area at the distal end  1102   a  of the light emitting section  1102 , allowing a greater quantity of light to be available at the distal end (unnumbered) of the light emitting section  1102 . The reason for this is that if the roughness of the light emitting section  1102  was consistent (not shown), more light would be emitted from the proximal end of the light emitting section  1102 , leaving less light available to be emitted from the distal end of the light emitting section  1102 . The result of a uniform roughness light emitting section  1102  (not shown) would be a light diffusing device (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  1100  shown in  FIG. 11  thus evenly emits the transmitted light energy along the length of the light emitting section  1102 , allowing safer and more precise photodynamic therapy. 
         [0303]      FIG. 12  shows the light emitting section  1202  of an embodiment of a light diffusing device  1200  of the present invention.  FIG. 12A  shows the entire light diffusing device  1200 , including a connector  1212  attached to the proximal end  1205  allowing the light diffusing device  1200  to be connected to a light source (not shown). As best shown in  FIG. 12B  the light diffusing device  1200  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  1210  made of PMMA (acrylic) surrounded by cladding  1208  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. The core fiber  1210  and cladding  1208  have different indexes of refraction, which enables light entering the light diffusing device  1200  at the connector  1212  to be transmitted along the length of the light diffusing device  1200  and therefore transmitted to a more distal location. The light diffusing device  1200  defines a distal end  1206  to which is attached a piercing tip  1214 , which prevents the escape of the transmitted light energy from an open distal end (not shown) of the core fiber  1210 . The piercing tip  1214  also allows the device  1200  to pierce or penetrate and thereby be implanted into tissue following the application of gentle force by the physician. In one embodiment, the piercing tip  1214  is made of machined (sharpened) stainless steel, however, this is not intended to be limiting as other metallic, composite and polymeric materials would also work. Using appropriate medical grade adhesives, the piercing tip  1214  is attached to the distal end  1206  of the optical fiber  10  after the distal end  1206  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive or erosive methods. 
         [0304]    The light emitting section  1202  is defined by a plurality of light ports  1204  which extend through the cladding  1208  exposing core fiber  1210  allowing the transmitted light energy to be emitted from the light diffusing device  1200 . As best shown in  FIG. 12 , the light emitting section  1202  is characterized by the light ports  1204  having a similar surface area and progressively denser in distribution (greater in number) as the distal end  1202   a  is reached. As shown in  FIG. 12B  the light ports  1204  are conically shaped and spacing may vary between 0.022 inches to 0.040 inches. Restated, a denser distribution of similarly sized light ports  1204  at the distal end  1202   a  results in a lesser exposed core fiber  1210  surface area at the proximal end  1202   b  of the light emitting section  1202  and a greater exposed core fiber  1210  surface area at the distal end  1202   a  of the light emitting section  1202 , allowing a greater quantity of light to be available at the distal end  1202   a  of the light emitting section  1202 . The reason for this is that if the distribution of light ports  1204  was even (not shown), more light would be emitted from the more proximally located light ports  1204 , leaving less light available to be emitted from the more distally located light ports  1204 . The result of evenly distributed light ports  1204  (not shown) would be an optical fiber (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  1200  shown in  FIGS. 12-12B  thus evenly emits the transmitted light energy along the length of the light emitting section  1202 , allowing safer and more precise photodynamic therapy. 
         [0305]      FIG. 13A  shows a top view of the light emitting section  1302  of an embodiment of the light diffusing device  1300  of the present invention. A side view is shown in  FIG. 13B , with phantom lines indicating the location and depth of the light port  1304 .  FIG. 13C  shows the entire light diffusing device  1300 , including a connector  1312  attached to the proximal end  1305  allowing the light diffusing device  1300  to be connected to a light source (not shown). As best shown in  FIGS. 13D ,  13 E,  13 F the light diffusing device  1300  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  1310  made of PMMA (acrylic) surrounded by cladding  1308  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. The core fiber  1310  and cladding  1308  have different indexes of refraction, which enables light entering the light diffusing device  1300  at the connector  1312  to be transmitted along the length of the light diffusing device  1300  and thereby transmitted to a more distal location. The light diffusing device  1300  defines a distal end  1306  to which is attached a piercing tip  1314 , preventing the escape of the transmitted light energy from an open distal end (not shown) of the core fiber  1310 . The piercing tip  1314  also allows the device  1300  to pierce or penetrate and thereby be implanted into tissue following the application of gentle force by the physician. The piercing tip  1314  in one embodiment is made of machined (sharpened) stainless steel, however, other metallic, composite and polymeric materials are also contemplated by and therefore within the scope of the invention. In this embodiment a section of fluorescent material  1316  is placed between the piercing tip  1314  and the distal end  1306  of the optical fiber  10 . The fluorescent material  1316  can be made of chromium crystal, however, this is not intended to be limiting as other materials including alexandrite, sapphire and others would also work. Using appropriate medical grade adhesives, the fluorescent material  1316  is attached to the distal end  1306  of the optical fiber  10  after the distal end  1306  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive or erosive methods. Following attachment of the fluorescent material  1316  to the optical fiber  10 , the piercing tip  1314  is attached to the distal end (unnumbered) of the fluorescent material  1316  using appropriate medical grade adhesives. The piercing tip  1314  prevents the escape of light energy through the distal end  1306  as well as facilitating direct introduction into tissue. The fluorescent material  1316  emits a signal when illuminated by light energy having a wavelength at least at an excitation wavelength and above and thus functions as a fluorescence feedback indicator. In this configuration, when the laser light source (not shown) is energized fluorescence occurs at the distal end  1306  and is detected at the light source console (not shown) to verify the light diffusing device  1300  is valid and functioning properly. In an alternative embodiment (not shown) the light diffusing device  1300  may be encased in a transparent protective sheath (not shown) which provides an additional degree of integrity as well as smoothness. 
         [0306]    The light emitting section  1302  is defined by an extended light port  1304  which is cut through the cladding  1308  into the core fiber  1300  allowing the transmitted light to be emitted from the light diffusing device  1300 . While a single extended light port  1304  is shown in  FIGS. 13-13F , this is for purposes of illustration only and the invention could also include multiple extended light ports  1304  (not shown). As best shown in  FIGS. 13D ,  13 E,  13 F, the light emitting section  1302  is characterized by the light port  1304  extending progressively deeper into the core fiber  1310  as the distal end  1302   a  is reached. Restated, the progressively deeper light port  1304  toward the distal end  1302   a  results in a lesser exposed core fiber  1310  surface area at the proximal end  1302   b  of the light emitting section  1302  and a greater exposed core fiber  1310  surface area at the distal end  1302   a  of the light emitting section  1302 , allowing a greater quantity of light to be available at the distal end (unnumbered) of the light emitting section  1302 . The reason for this is that if the depth of the light port  1304  was consistent (not shown), more light would be emitted from the proximal end of the light port  1304 , leaving less light available to be emitted from the distal end of the light port  1304 . The result of a uniform depth light port  1304  (not shown) would be an optical fiber (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  1300  shown in  FIG. 13  thus evenly emits the transmitted light energy along the length of the light emitting section  1302 , allowing safer and more precise photodynamic therapy. 
         [0307]      FIG. 14  shows the light emitting section  1402  of an embodiment of the light diffusing device  1400  of the present invention.  FIG. 14A  shows the entire light diffusing device  1400 , including a connector  1412  attached to the proximal end  1405  allowing the light diffusing device  1400  to be connected to a light source (not shown). As best shown in  FIGS. 14B ,  14 C,  14 D the light diffusing device  1400  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  1410  made of PMMA (acrylic) surrounded by cladding  1408  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. In this embodiment, the light diffusing device  1400  is also covered by sheathing  1418  which serves to further protect the device  1400 . The sheathing  1418  can be polymeric materials such as PTFE, polyester, polyurethane, PMMA, PEBAX or other suitable materials and can be applied by heat shrink, non-heat shrink techniques or adhesive techniques (i.e., epoxy and uv cured materials, among others). The core fiber  1410  and cladding  1408  have different indexes of refraction, which enables light entering the light diffusing device  1400  at the connector  1412  to be transmitted along the length of the light diffusing device  1400  and thereby transmitted to a more distal location. The light diffusing device  1400  defines a distal end  1406  to which is attached a piercing tip  1414 , preventing the escape of the transmitted light energy from an open distal end (not shown) of the core fiber  1410 . The piercing tip  1414  also allows the device  1400  to pierce or penetrate and thereby be implanted into tissue following the application of gentle force by the physician. In one embodiment, the piercing tip  1414  is made of machined (sharpened) stainless steel, however, this is not intended to be limiting as other metallic, composite and polymeric materials could also be used. Using appropriate medical grade adhesives, the piercing tip  1414  is attached to the distal end  1406  of the light diffusing device  1400  after the distal end  1406  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive or erosive methods. 
         [0308]    The light emitting section  1402  is defined by an extended light port  1404  which is cut through the cladding  1408  exposing the core fiber  1400  allowing the transmitted light to be emitted from the light diffusing device  1400 . While a single extended light port  1404  is shown in  FIGS. 14-14D , this is for purposes of illustration only and the invention could also include multiple extended light ports  1404  (not shown). As best shown in  FIGS. 14B ,  14 C,  14 D, the light emitting section  1402  is characterized by the light port  1404  extending progressively wider through the cladding  1408  as the distal end is reached. Restated, the progressively wider light port  1404  toward the distal end results in a lesser exposed core fiber  1410  surface area at the proximal end  1402   b  of the light emitting section  1402  and a greater exposed core fiber  1410  surface area at the distal end  1402   a  of the light emitting section  1402 , allowing a greater quantity of light to be available at the distal end  1402   a  of the light emitting section  1402 . The reason for this is that if the width of the light port  1404  was consistent (not shown), more light would be emitted from the proximal end  1402   b  of the light port  1404 , leaving less light available to be emitted from the distal end  1402   a  of the light port  1404 . The result of a uniform width light port  1404  (not shown) would be an optical fiber (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  1400  shown in  FIG. 14  thus evenly emits the transmitted light energy along the length of the light emitting section  1402 , allowing safer and more precise photodynamic therapy. 
         [0309]      FIG. 15  shows the light emitting section  1502  of an embodiment of a light diffusing device  1500  of the present invention.  FIG. 15A  shows the entire light diffusing device  1500 , including a connector  1512  attached to the proximal end  1505  allowing the light diffusing device  1500  to be connected to a light source (not shown). As best shown in  FIG. 15B  the light diffusing device  1500  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  1510  made of PMMA (acrylic) surrounded by cladding  1508  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. In this embodiment, the light diffusing device  1500  is also covered by sheathing  1518  which serves to further protect the device  1500 . The sheathing  1518  can be polymeric materials such as PTFE, polyester, polyurethane, PMMA, PEBAX or other suitable materials and can be applied by heat shrink, non-heat shrink techniques or adhesive techniques (i.e., epoxy and uv cured materials, among others). The core fiber  1510  and cladding  1508  have different indexes of refraction, which enables light entering the light diffusing device  1500  at a proximal location to be transmitted along the length of the light diffusing device  1500  and thereby transmitted to a more distal location. The light diffusing device  1500  defines a distal end  1506  which comprises a piercing tip  1514 , preventing the escape of the transmitted light energy from an open distal end (not shown) of the core fiber  1510 . The piercing tip  1514  also allows the device  1500  to pierce or penetrate tissue following the application of gentle force by the physician, allowing the device  1500  to be implanted into tissue. In one embodiment, the piercing tip  1514  is made of machined (sharpened) stainless steel, however, this is not intended to be limiting as other metallic, composite and polymeric materials could also be used. In this embodiment a section of fluorescent material  1516  is attached to the distal end  1506  of the optical fiber  10  using appropriate medical grade adhesive before attaching the piercing tip  1514 . Using appropriate medical grade adhesives, the piercing tip  1514  is then attached to the distal end  1506  of the light diffusing device  1500  after the distal end (unnumbered) of the fluorescent material  1516  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive methods. The fluorescent material  1516  emits a signal when illuminated by light energy having a wavelength at least at an excitation wavelength and above and thus functions as a fluorescence feedback indicator. In this configuration, when the laser light source (not shown) is energized fluorescence occurs at the distal end  1506  and is detected at the light source console (not shown) to verify the light diffusing device  1500  is valid and functioning properly. In another embodiment (not shown) the end piece  1514  may be omitted and replaced by other light blocking mechanisms including opaque epoxy or plastic materials. 
         [0310]    The light emitting section  1502  is defined by a plurality of light ports  1504  which extend through the cladding  1508  exposing core fiber  1510  allowing the transmitted light energy to be emitted from the light diffusing device  1500 . As best shown in  FIG. 15 , the light emitting section  1502  is characterized by the light ports  1504  progressively exposing a greater core fiber  1510  surface area as the distal end  1506  is reached. The light ports  1504  are conically shaped and spacing may vary in diameter between 0.003 inches to 0.006 inches. Restated, progressively greater sized light ports  1504  toward the distal end  1502   a  result in a lesser exposed core fiber  1510  surface area at the proximal end  1502   b  of the light emitting section  1502  and a greater exposed core fiber  1510  surface area at the distal end  1502   a  of the light emitting section  1502 , allowing a greater quantity of light to be available at the distal end  1506  of the light emitting section  1502 . The reason for this is that if the surface area of the light ports  1504  was consistent (not shown), more light would be emitted from the more proximally located light ports  1504 , leaving less light available to be emitted from the more distally located light ports  1504 . The result of similarly sized light ports  1504  (not shown) would be an optical fiber (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  1500  shown in  FIGS. 15-15B  thus evenly emits the transmitted light energy along the length of the light emitting section  1502 , allowing safer and more precise photodynamic therapy. 
         [0311]      FIG. 16  shows the light emitting section  1602  of an embodiment of a light diffusing device  1600  of the present invention.  FIG. 16A  shows the entire light diffusing device  1600 , including a connector  1612  attached to the proximal end  1605  allowing the light diffusing device  1600  to be connected to a light source (not shown). As best shown in  FIGS. 16B ,  16 C,  16 D the light diffusing device  1600  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  1610  made of PMMA (acrylic) surrounded by cladding  1608  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. In this embodiment, the light diffusing device  1600  is also covered by sheathing  1618  which serves to further strengthen and protect the device  1600 . The sheathing  1618  can be polymeric materials such as PTFE, polyester, polyurethane, PMMA, PEBAX or other suitable materials and can be applied by heat shrink, non-heat shrink techniques or adhesive techniques (i.e., epoxy and uv cured materials, among others). The core fiber  1610  and cladding  1608  have different indexes of refraction, which enables light entering the light diffusing device  1600  at the connector  1612  to be transmitted along the length of the light diffusing device  1600  and thereby transmitted to a more distal location. The optical fiber  10  defines a distal end  1606  to which a section of fluorescent material  1616  is attached using appropriate medical grade adhesive. The fluorescent material  1616  emits a signal when illuminated by light energy having a wavelength at least at an excitation wavelength and above and thus functions as a fluorescence feedback indicator. In this configuration, when the laser light source (not shown) is energized fluorescence occurs at the distal end  1606  and is detected at the light source console (not shown) to verify the light diffusing device  1600  is valid and functioning properly. In this embodiment, the piercing tip of other embodiments is replaced by encapsulating the fluorescent material  1616  with sheathing  1618  which is hardened and sharpened to form a piercing distal end  1614 . This allows the device  1600  to pierce or penetrate tissue upon the application of gentle force by the physician. 
         [0312]    The light emitting section  1602  is defined by a plurality of light ports  1604  which extend through the cladding  1608  into the core fiber  1600  allowing the transmitted light to be emitted from the light diffusing device  1600 . As best shown in  FIGS. 16B ,  16 C,  16 D, the light emitting section  1602  is characterized by the light ports  1604  having a similar surface area that extend progressively deeper into the core fiber  1610  as the distal end  1602   a  is reached. The light ports  1604  are conically shaped and the depth may vary between 0.004 inches to 0.008 inches. Restated, progressively deeper, similarly sized light ports  1604  toward the distal end  1602   a  result in a lesser exposed core fiber  1610  surface area at the proximal end  1602   b  of the light emitting section  1602  and a greater exposed core fiber  1610  surface area at the distal end  1602   a  of the light emitting section  1602 , allowing a greater quantity of light to be available at the distal end  1602   a  of the light emitting section  1602 . The reason for this is that if the size and depth of light ports  1604  was consistent (not shown), more light would be emitted from the more proximally located light ports  1604 , leaving less light available to be emitted from the more distally located light ports  1604 . The result of similarly sized and depth light ports  1604  (not shown) would be an optical fiber (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  1600  shown in  FIG. 16  thus evenly emits the transmitted light energy along the length of the light emitting section  1602 , allowing safer and more precise photodynamic therapy. 
         [0313]      FIG. 17  shows the light emitting section  1702  of an embodiment of the light diffusing device  1700  of the present invention. A plan view of the light emitting section as shown in  FIG. 17A  shows the entire light diffusing device  1700 , including a connector  1712  attached to the proximal end  1705  allowing the light diffusing device  1700  to be connected to a light source (not shown). As best shown in  FIG. 17B  the light diffusing device  1700  is made for reasons of economy as well as flexibility from a plastic optical fiber  10  approximately 1 mm in diameter which comprises a light transmitting core fiber  1710  made of PMMA (acrylic) surrounded by cladding  1708  made of fluorinated polymers. It should be mentioned that other kinds of light transmitting fibers (not shown) could also be used and are therefore contemplated by and within the scope of the invention. The core fiber  1710  and cladding  1708  have different indexes of refraction, which enables light entering the light diffusing device  1700  at the connector  1712  to be transmitted along the length of the light diffusing device  1700  and thereby transmitted to a more distal location. The light diffusing device  1700  defines a distal end  1706  to which is attached an opaque end piece  1714 , preventing the escape of the transmitted light energy from an open distal end (not shown) of the core fiber  1710 . In one embodiment, the end piece  1714  is made of stainless steel. Using appropriate medical grade adhesives, the end piece  1714  is attached to the distal end  1706  of the light diffusing device  1700  after the distal end  1706  is roughened by such means as sandpaper, sandblasting, chemical degradation or other abrasive methods. In another embodiment (not shown) the end piece  1714  may be omitted and replaced by other light blocking mechanisms including opaque epoxy or plastic materials. In an alternative embodiment (not shown) the light diffusing device  1700  may be encased in a transparent protective sheath (not shown) which provides an additional degree of integrity as well as smoothness. 
         [0314]    In this embodiment the light diffusing device  1700  the cladding  1708  is not removed. The light emitting section  1702  is defined by progressively distally roughening the surface of the cladding  1708  defining the light emitting section  1702  allowing an increased amount of transmitted light to be emitted from the light diffusing device  1700 . As best shown in  FIG. 17  the light emitting section  1702  is characterized by the light emitting section  1702  having a relatively smooth area  1704   b  which becomes progressively rougher  1704   a  along the core fiber  1710  as the distal end  1702   a  is reached. Restated, the progressively rougher light emitting section  1702  toward the distal end  1702   a  results in a lesser exposed core fiber  1710  surface area at the proximal end  1702   b  of the light emitting section  1702  and a greater exposed core fiber  1710  surface area at the distal end  1702   a  of the light emitting section  1702 , allowing a greater quantity of light to be available at the distal end (unnumbered) of the light emitting section  1702 . The reason for this is that if the roughness of the light emitting section  1702  was consistent (not shown), more light would be emitted from the proximal end of the light emitting section  1702 , leaving less light available to be emitted from the distal end of the light emitting section  1702 . The result of a uniform roughness light emitting section  1702  (not shown) would be a light diffusing device (not shown) having uneven light distribution, with more intensity toward the proximal end and less toward the distal end. The embodiment of the light diffusing device  1700  shown in  FIG. 17  thus evenly emits the transmitted light energy along the length of the light emitting section  1702 , allowing safer and more precise photodynamic therapy. 
         [0315]    The light ports  104 ,  204 ,  304 ,  404 ,  504 ,  1204 ,  1304 ,  1404 ,  1504 ,  1604  and removed core fiber sections  604 ,  704 ,  804 ,  904 ,  1004  are created by securing a virgin plastic optical fiber (not shown) in a fixture (not shown) and then energizing a CO 2  laser (not shown) focused in the appropriate location(s). In one embodiment the fixture (not shown) is translated only on the X axis which moves longitudinally and rotates in order to create the light ports  104 ,  304 ,  404 ,  1204 ,  1304 ,  1404 ,  1504 ,  1604  and removed core fiber sections  604 ,  704 ,  804 ,  904 ,  1004 . In embodiments  200 ,  500 ,  1400 ,  1500 ,  1600  which have a wider light port  204 ,  504 ,  1404 ,  1504 ,  1604 , removed core fiber section  900  or deeper light port  300 ,  400 , is required, the fixture (not shown) may additionally translate in the Y axis, moving the CO 2  laser closer to the virgin optical fiber (not shown). In another embodiment, repositioning of the optical fiber (not shown) in the fixture (not shown) may be required to allow for the creation of light ports  104 ,  204 ,  304 ,  404 ,  504 ,  1104 ,  1204 ,  1304 ,  1404 ,  1504 ,  1604  or removed core fiber sections  604 ,  704 ,  804 ,  904 ,  1004  that would be covered by the mandrel during an earlier laser drilling treatment. When energized, the laser pulse of the CO 2  laser (not shown) may have a 10.6 micron wavelength at 5 watts with a pulse duration between approximately 0.0003 to 0.0010 seconds. This results in controlled removal of the cladding  108 ,  208 ,  308 ,  408 ,  508 ,  1104 ,  1204 ,  1304 ,  1404 ,  1504 ,  1604  and in some cases part of the core fiber  110 ,  210 ,  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  910 ,  1010 ,  1110 ,  1210 ,  1310 ,  1410 ,  1510 ,  1610  without unduly damaging the core fiber  110 ,  210 ,  310 ,  410 ,  510 ,  610 ,  710 ,  810 ,  910 ,  1010 ,  1110 ,  1210 ,  1310 ,  1410 ,  1510 ,  1610 . In the case of the embodiment of the light diffusing device  1100  the cladding is first removed from the section of the optical fiber  10  desired to become the light emitting section  1102 , in the embodiment as shown, toward the distal end of the light diffusing device  1100 . The embodiment of the light diffusing device  1700  does not require removal of any cladding  1708 . Next, the light emitting section  1102 ,  1702  is treated with abrasives such as sandpaper, sand blasting or other abrasive techniques, starting at the proximal end  1102   b,    1702   b  of the light emitting section  1102 ,  1702  and progressing for a longer period in a distal direction until the distal end  1102   a,    1702   a  is reached. This results in a light emitting section  1102 ,  1702  which is progressively rougher in a distal direction. 
       Use 
       [0316]    Using the light diffusing device  100 ,  200 ,  300 ,  400 ,  500 ,  600 ,  700 ,  800 ,  900 ,  1000 ,  1100 ,  1200 ,  1300 ,  1400 ,  1500 ,  1600 ,  1700  of the present invention involves initially treating the patient at the treatment site with a photosensitizing agent such as methylene blue or another of many photosensitizing agents well known in the art. Depending on the nature of the photodynamic therapy treatment, a period of time may be required to allow for absorption of the particular photosensitizing agent into the affected tissue. The light diffusing device  100 ,  200 ,  300 ,  400 ,  500 ,  600 ,  700 ,  800 ,  900 ,  1000 ,  1100 ,  1200 ,  1300 ,  1400 ,  1500 ,  1600 ,  1700  is removed from sterile packaging followed by positioning it in the treatment area. In the embodiments  1200 ,  1300 ,  1400 ,  1500 ,  1600  configured to be tissue piercing or penetrating, gentle pressure is applied to the device  1200 ,  1300 ,  1400 ,  1500 ,  1600  by the physician, causing it to become implanted into the intended tissue requiring treatment. Via the connector  112 ,  212 ,  312 ,  412 ,  512 ,  612 ,  712 ,  812 ,  912 ,  1012 ,  1112 ,  1212 ,  1312 ,  1412 ,  1512 ,  1612 ,  1712  the light diffusing device  100 ,  200 ,  300 ,  400 ,  500 ,  600 ,  700 ,  800 ,  900 ,  1000 ,  1100 ,  1200 ,  1300 ,  1400 ,  1500 ,  1600 ,  1700  is connected to a light source (not shown) capable of producing light in the appropriate wavelength which varies with the particular photosensitizing agent used and treatment prescribed, followed by energizing the light source at the beginning of treatment. The light source is then energized for the prescribed length of time and intensity (which also varies with the particular photosensitizing agent used) then de-energized at the conclusion. Following the conclusion of treatment, the light diffusing device  100 ,  200 ,  300 ,  400 ,  500 ,  600 ,  700 ,  800 ,  900 ,  1000 ,  1100 ,  1200 ,  1300 ,  1400 ,  1500 ,  1600 ,  1700  is disposed of.