Side-firing laser optical fiber probe and method of making same

A laser optical fiber probe has a silica fiber core with an end terminating in an inclined surface. A silica capsule encloses the end of the fiber and locates the end of the fiber in a gas chamber. Localized heat fuses the end of the fiber opposite the inclined surface to the capsule thereby eliminating secondary light reflections.

FIELD OF INVENTION 
The invention relates to medical devices used for treating a human body 
with laser energy transmitted through an optical fiber 
BACKGROUND OF INVENTION 
Lasers used in medicine and dental application have a light energy output 
that can be controlled for providing thermal treatment to disease and 
traumatized tissues. Optical fibers provide a means for delivering laser 
radiation with minimal energy loss to remote tissue locations within the 
body. Some therapeutic procedures require that the laser radiation be 
delivered laterally or generally perpendicular to the fiber optic probe. 
One system to accomplish the beam deflection uses a gold plated mirror 
positioned at the distal end of the fiber optic probe. The mirror is held 
in place by a metal tip. The laser energy is reflected off of the gold 
surface which must be cooled and kept clean to avoid damage. Another 
system uses a fiber optic probe that has an angle polish on the distal end 
thereof. The fiber is placed in a quartz tube to provide a fiber/air 
interface. An example of the fiber optic probe is disclosed by Vassileadis 
and Hennings in U.S. Pat. No. 5,129,895. These probes can have a 
substantial amount of unwanted reflected and refracted laser radiation. 
SUMMARY OF THE INVENTION 
The invention is a laser optical fiber probe and method making the probe 
operable to direct light energy laterally of the probe with minimal light 
scattering and unwanted light reflections. The probe incorporates fresnel 
light reflections from the optical fiber and air interface laterally into 
the fiber and capsule enclosing the end of the fiber without secondary 
light reflections and refractions. The probe is essentially not wavelength 
selective and operates to deliver high power laser light laterally out of 
the probe. The probe is usable for therapeutic procedures, such as 
endoscopic surgery and diagnostic procedures. 
The probe includes a laser optical fiber having a distal end with a least 
one inclined polished surface. The distal end of the fiber can be cut to 
provide two or more inclined surfaces or provided with a cone-shaped 
recess forming a cone surface. The surface is polished or covered with 
coating materials, such as metal film or dielectric materials. A laser 
beam from a laser propagates down the optical fiber to the inclined 
surface and is reflected laterally from the surface or coating materials 
and probe. The distal end of the optical fiber including the inclined 
surface or coating materials is located in a sealed air chamber provided 
by a tip or capsule surrounding the end of the optical fiber. A portion of 
the distal end of the optical fiber opposite the inclined surface is 
united with heat to the capsule. The heat melts adjacent portions of the 
fiber and capsule to fuse them together. This eliminates the 
fiber-air-capsule interfaces that result in undesirable reflected light. 
The light from the inclined surface is reflected laterally through the 
combined materials, such as silica, of the fiber and capsule without 
producing unwanted reflected and refractive light. 
A preferred embodiment of the probe has an elongated laser optical fiber of 
silica enclosed within a cladding of doped fused silica. The distal end of 
the fiber has an inclined surface polished at an angle of 37 degrees 
relative to the longitudinal axis of the fiber. The light reflected from 
the inclined surface, according to fresnels law, emerges at approximately 
70 degrees in air with an associated divergence. A capsule comprising a 
tubular member of silica having a closed end provides support and an air 
chamber for the distal end of the optical fiber. A portion of the optical 
fiber opposite the inclined surface is united or fused with heat, 
1400.degree. to 1700.degree. C., generated with a carbon dioxide 
(CO.sub.2) laser beam to the adjacent portion of the tubular member. The 
fusing of the fiber with the tubular member results in common continuous 
silica from the inclined surface to the exterior of the tubular member. 
There are no interfaces that reflect and refract light other than the 
light reflected from the inclined surface. The fusing of the fiber with 
the tubular member also provides structural support for the tubular member 
and inhibits removal of the tubular member from the fiber. 
The invention includes the methods to manufacture the probe having an 
optical fiber fused to a tubular member to eliminate unwanted light 
reflections and refractions. The distal end of the optical fiber is cut at 
an inclined angle to provide an inclined end surface. The surface is 
polished at the inclined angle. A coating material, such as a metal film 
or dielectric material, can be secured to the surface. The distal end of 
the fiber can be cut at several angles, such as a V-groove, to provide 
separate inclined surfaces. A cone-shaped recess can be drilled into the 
distal end of the fiber to provide a cone-shaped surface. A laser beam can 
be used to cut a general cone-shaped recess in the distal end of the 
fiber. Longitudinal movement of the laser beam used to fuse the fiber to 
the tubular member can be used to establish a general cone-shaped recess 
in the end of the fiber. These surfaces are polished or covered with 
coating material. The distal end of the optical fiber is longitudinally 
inserted into a tubular member having a closed end. The inclined surface 
or coating material is spaced from the inside of the closed end of the 
tubular member to locate the inclined surface in an enclosed air chamber. 
Localized high heat, 1400.degree. to 1700.degree. C., generated with laser 
unites or fuses the silica of the fiber opposite the inclined surface to 
the silica of the tubular member to join and merge the silica together. 
During the fusing process, the fusing progress is monitored visually or by 
instrumentation.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIG. 1, there is shown a diagrammatic view of a laser catheter 
indicated generally at 10, used in radiation medical treatment and 
diagnostic procedures. Catheter 10 has an elongated flexible optical fiber 
11 that is trained through a handle 12 such as an endoscope 12. The distal 
end of the optical fiber 11 has a probe 13. The optical fiber 11 is joined 
to a connector 14 that receives light energy from a laser 15 through 
optical system 16. 
Referring to FIGS. 1-6, there is shown a conventional optical fiber probe, 
indicated generally at 13, for lateral beaming or side-firing of a laser 
beam. Probe 13 has a central elongated optical fiber 17 made of glass, 
plastic or fused silica terminating in an end having an inclined flat 
surface 18. Surface 18 is inclined at about an angle of between 37 and 45 
degrees with respect to the longitudinal center line of fiber 17. Surface 
18 can be inclined at other angles relative to the longitudinal center 
line of fiber 17. The inclined angle of the distal end 18 of fiber 17 is 
37 degrees. Fiber 17 is enclosed within a cladding 19 of silica material 
having an index of refraction lower than the index of refraction of the 
core so as to maintain the laser light in fiber 17. A tubular sleeve 20 of 
plastic material surrounds layer 19 to protect the integrity of fiber 17. 
A plastic jacket 21 covers sleeve 20. 
A transparent capsule or tubular member 22 secured to jacket 21 surrounds 
the distal end of fiber 17 including inclined end 18. Member 22 has a 
generally convex curved closed end 23 and an internal chamber 24 that 
accommodates a gas, such as air. The distal end of fiber 17, including the 
inclined end 18, are spaced from the inside walls of tubular member 22 
whereby air surrounds the entire distal end of fiber 17. 
In use, referring to FIGS. 5 and 6, laser beam 25 axially propagates along 
fiber 17 and reflects off of inclined surface 18 as primary reflective 
light 26, which is directed generally laterally of probe 13. The light 26 
must pass through the air chamber 24 and through the material of tubular 
member 22. Part of the light reflects off of fiber 17 and the inside 
surface 28 of tubular member 22 and is directed in an opposite direction 
from the primary reflected light indicated by the secondary reflected 
light 27. Some of the light from laser beam 27 is additional secondary 
light 29. As seen in FIG. 6, light 29 is directed outwardly adjacent 
opposite sides of primary light 26. The reflected light 27 and light 29 
are unwanted and potentially unsafe light. This light stems from multiple 
changes in the refractive indices in the exit path of the laser beam. 
Referring to FIGS. 7-11, there is shown the side-firing laser optic fiber 
probe of the invention, indicated generally at 113. Probe 113 has an 
elongated flexible optical fiber 117 terminating in an inclined end 
surface 118. Fiber 117 has a silica fiber core surrounded with a doped 
fused silica cladding 119. A sleeve 120 of plastic material covers 
cladding 119. The cladding 119 is enclosed within a jacket (not shown) of 
plastic material, such as Teflon. Surface 118 has a generally oval 
polished shape. A diamond-tipped abrasive tool, a carbon dioxide 
(CO.sub.2) laser tightly focused or excimer laser can be used to polish 
surface 118. These polishing methods are examples of polishing technology 
for polishing surface 118. Other polishing procedures can be used to 
create the desired surface characteristics on surface 118. Surface 118 is 
inclined forwardly at an angle of 37 degrees relative to the longitudinal 
axis of fiber 117. The inclined angle of surface 118 can be between 37 to 
45 degrees relative to the longitudinal axis of fiber 117. Other angles 
can be used for surface 118. When the angle of surface 118 is 37 degrees, 
the reflected light will emerge at approximately 70 degrees in air with an 
associated divergence. A tubular layer of silica cladding 119 surrounds 
the core of fiber 117 to protect the core and maintain the laser light 
within fiber 117. A transparent capsule or tubular member 122 of silica 
having a closed convex curved end 123 is located about the distal end of 
fiber 117 to enclose the distal end of fiber 117 within an air chamber 
124. The distal end of fiber 117 is surrounded by air chamber 124. Member 
122 is a silica cylindrical tubular member made of silica material the 
same as or similar to the silica material of fiber 117. 
The distal end of fiber 117 is united at 125 to the adjacent inside wall of 
tubular member 122. The silica materials of fiber 117 and tubular member 
122 are fused with localized heat. As shown in FIG. 7, the heat required 
to cause the fusion of the silica materials of fiber 117 and tubular 
member 122 is in the range of 1400.degree. to 1700.degree. C. A laser beam 
127 directed through an optical lens 128 which concentrates the laser beam 
on the surface of tubular member 122. The heat from the laser beam 127 is 
conducted through the silica of tubular member 122 toward the distal end 
of fiber 117 to the area 129 opposite surface 118. The high temperature 
heat radiates across the air gap and melts the silica opposite surface 118 
as well as the silica of tubular member 122. The silica materials within 
area 129 are melted and fused together as shown in FIGS. 8-11. Laser beam 
127 is generated by a carbon dioxide (CO.sub.2) laser 132. Other types of 
laser energy and heat sources can be used to unite the end of fiber 117 to 
the inside of tubular member 122. 
Probe 133 is made by providing an elongated optical fiber adapted to be 
coupled to a laser used to direct a laser beam or light along the fiber. 
The optical fiber has a fused silica fiber core enclosed within a doped 
silica cladding 119 and a sleeve 120, covered with a plastic jacket. The 
distal end of fiber 117 is cut at an angle of 37 degrees relative to the 
longitudinal axis of fiber 117 to provide inclined oval surface 118. 
Surface 118 is polished with a diamond-tipped abrasive tool, carbon 
dioxide (CO.sub.2) laser, or excimer laser to provide a smooth and flat 
surface. A silica capsule or tubular member 122, having a closed end 123 
and air chamber 124, is provided to accommodate and support the distal end 
of fiber 117. The distal end of fiber 117 is inserted through the open end 
of tubular member 122 into air chamber 124. Tubular member 122 is then 
secured to the sleeve with surface 118 spaced from the closed end 123 of 
member 122. A heat source 132 generating a carbon dioxide (CO.sub.2) laser 
beam 127 provides heat in the range of 1400.degree. to 1700.degree. C. 
which is applied to tubular member 122 adjacent the end of fiber 117. The 
heat is localized on the end of fiber 117 opposite surface 118 and 
adjacent material of tubular member 122 to unite or fuse fiber 117 to 
member 122 in area 129 of fiber 117 and tubular member 122 opposite 
surface 118. As seen in FIGS. 9 and 11, fused area 125 has a 
circumferential length of about 100 degrees. Other circumferential or 
arcuate lengths of fused area 125 can be used to connect fiber 117 to 
member 122. The progress of the fusing process is monitored visually or by 
instrumentation. 
Referring to FIGS. 10 and 11, light or laser beam 130 generated by a laser 
axially propagates down fiber 117. When light 130 encounters a change in 
refractive index, it laterally redirects the light energy indicated by 
arrows 131. The angle of polished surface 118 being 37 degrees relative to 
the longitudinal axis of fiber 117 results in almost total internal 
reflection of light 130 as redirected light 131 at an angle of 
approximately 70 degrees relative to the longitudinal axis of fiber 117. 
Light 131 is efficiently redirected laterally through the distal end of 
fiber 117, the fused area 125 and tubular member 122. Fiber 117, fused 
area 125 and tubular member 122, being of the same silica materials, do 
not produce changes in the refractive indices and thereby do not produce 
reflected light nor secondary light. Reflections that stem from multiple 
changes in the refractive indices in the exit path of the laser beam are 
eliminated. Probe 113 is a reliable means to efficiently deliver high 
energy laser light that is essentially not wavelength selective. Probe 113 
is used in surgical procedures, such as endoscopic surgery. The laser 
light directed laterally from probe 113 vaporizes the tissue thereby 
reducing the size of the tissue gland. Probe 113 is also usable in 
diagnostic procedures to determine location and size of in vivo tissues. 
Low level laser light is directed laterally from probe 113 into tissue. 
The laser light causes the tissue to fluorescence. A portion of this 
fluorescence is directed back towards probe 113. The probe 113 senses the 
intensity of the fluorescent light and transmits the light back along the 
fiber core. Changes in the intensity and spectrum of the reflected light 
are recorded and analyzed to provide information as to the condition of in 
vivo tissue. 
Referring to FIGS. 12-17, there is shown a first modification of the 
side-firing laser optical fiber probe of the invention, indicated 
generally at 213. Probe 213 has an elongated flexible optical fiber 217 
terminating in an inclined end surface 218. Coating material 226 attached 
to surface 218 reflects light laterally of optical fiber 217. Coating 
material 226 is a film of metal or dielectric material bonded to surface 
218. The metal film can be gold, silver or other metals that reflect 
light. The dielectric material can be several layers of non-conductive 
materials united to surface 218. Fiber 217 has a silica fiber core 
surrounded with a doped fused silica cladding 219. Surface 218 and coating 
material 226 are inclined forwardly at an angle of 37 degrees relative to 
the longitudinal axis of fiber 217. Other angles can be used for surface 
218 and coating material. The light reflection characteristics of metal 
film and dielectric coating materials are not sensitive to the angle at 
the distal end of fiber 217. Angles outside of the range of 37 to 45 
degrees can be used for coating material 226 to reflect light laterally 
relative to the longitudinal axis of optical fiber 217. When the angle of 
coating material 226 is 37 degrees, the reflected light will emerge at 
approximately 70 degrees in air with an associated divergence. A tubular 
layer of polymer material 220 surrounds cladding 219 to protect fiber 217 
and cladding 219. A jacket of plastic material, such as Teflon, surrounds 
polymer material 220. A transparent capsule or tubular member 222 having a 
closed convex curved end 223 is located about the distal end of fiber 217 
within a gas chamber 224. The distal end of fiber 217 and coating material 
226 is surrounded by gas chamber 224. Member 222 is a silica cylindrical 
tubular member made of silica material the same as or similar to the 
silica material of fiber 217. 
The distal end of fiber 217 is united at 225 to the inside wall 227 of 
tubular member 222. The materials of the fiber and tubular member are 
fused with localized heat. The heat, 1400.degree. to 1700.degree. C., 
required to cause the fusion of the silica materials of fiber 217 and 
tubular member 222 is supplied by a laser beam, as shown in FIG. 7. The 
laser used to fuse the silica of fiber 217 to tubular member 222 can be a 
carbon dioxide laser. 
Probe 233 is made by providing an elongated optical fiber 217 adapted to be 
coupled to a laser used to direct a laser beam or light along the fiber. 
The fiber has a silica fiber core enclosed within a silica cladding 219. 
The fiber core and cladding 219 are covered with a plastic sleeve 220 and 
a plastic jacket 221. The coating material 226 is secured to surface 218. 
The entire surface 218 is covered with a film of layer of coating material 
226. The distal end of fiber 217 is cut at a selected angle, such as an 
angle of 37 degrees relative to the longitudinal axis of fiber 217 to 
provide inclined oval surface 218. A tubular member 222, having a closed 
end 223 and an air chamber 224, is provided to accommodate and support the 
distal end of fiber 217. The distal end of fiber 217 is inserted through 
the open end of tubular member 222 into air chamber 224. Tubular member 
222 is then secured to sleeve 220 and jacket 221 with coating material 226 
spaced from the inside of closed end 223 of member 222. A heat source, 
such as a carbon dioxide (CO.sub.2) laser beam, is used to heat the silica 
at the end of fiber 217 opposite surface 218 and adjacent material of 
tubular member 222 to unite or fuse fiber 217 to member 222 in area 225 
opposite surface 218. As seen in FIGS. 15 and 17, fused area 225 has a 
circumferential length of about 100 degrees. Other circumferential or 
arcuate lengths of fused area 225 can be used to connect fiber 217 to 
member 222. The progress of the fusing process is monitored visually or by 
instrumentation, 
Referring to FIGS. 16 and 17, light or laser beam 230 generated by a laser 
(not shown) axially propagates down fiber 217. When light 230 encounters 
coating material 226, it redirects or reflects light energy indicated by 
arrows 231. The angle of coating material 226, being 37 degrees relative 
to the longitudinal axis of fiber 217, results in reflection of light 230 
as redirected light 231 at an angle of approximately 70 degrees relative 
to the longitudinal axis of fiber 217. When coating material 226 is 
positioned at angles different than 37 degrees, light 230 will be 
redirected laterally at angles related to the different angle or positions 
of coating material 226. Light 230 is efficiently redirected laterally 
through fiber 217, the fused area 225 and member 222. Fiber 217, fused 
area 225 and member 222, being of the same silica materials, do not 
produce changes in the refractive indices and thereby do not produce 
reflected light nor secondary refractive light. Reflections that stem from 
multiple changes in the refractive indices in the exit path of the laser 
beam are eliminated. Probe 213 is a reliable means to efficiently deliver 
high energy laser light that is essentially not wavelength selective. 
Referring to FIGS. 18-24, there is shown a second modification of the 
side-firing laser optical fiber probe of the invention, indicated 
generally at 313. Probe 313 has an elongated flexible optical fiber 317 
terminating in two outwardly and forwardly inclined end surfaces 315 and 
318. Fiber 317 has a silica fiber core surrounded with a doped fused 
silica cladding 319. Surfaces 315 and 318 diverge outwardly and forwardly 
whereby the distal end of fiber 317 has a V-shaped groove. A 
diamond-tipped abrasive tool, a carbon dioxide (CO.sub.2) laser tightly 
focused or excimer laser can be used to polish surfaces 315 and 318. 
Surfaces 315 and 318 can be covered with coating material, such as a gold 
or silver film or dielectric material. Surfaces 315 and 318 are inclined 
forwardly at an angle of 37 degrees relative to the longitudinal axis of 
fiber 317. Other angles can be used for surfaces 315 and 318. When the 
angles of surfaces 315 and 318 are 37 degrees, the reflected light will 
emerge at approximately 70 degrees in air with an associated divergence. 
Tubular cladding 319 surrounds fiber 317 to protect the fiber and maintain 
the laser light within fiber 317. A jacket 321 of plastic material 
surrounds cladding 319 and a sleeve 320 of plastic material. A transparent 
capsule or tubular member 322 is located about the distal end of fiber 317 
to enclose the distal end of fiber 317 within a gas chamber 324. The gas 
is air. The distal end of fiber 317 is surrounded by chamber 324. Member 
322 is a silica cylindrical tubular member made of silica material the 
same as or similar to the silica material of fiber 317. 
The distal end of fiber 317 is united at 325 and 336 to the inside wall of 
tubular member 322. The materials of the fiber and tubular member are 
fused with localized heat. As shown in FIG. 20, the heat in the range of 
1400.degree. to 1700.degree. C. required to cause the fusion of the silica 
materials of fiber 317 and tubular member 322 is supplied by a first laser 
332 generating laser beam 327 directed through an optical lens 328 which 
concentrates the laser beam 327 on the surface of tubular member 322. The 
heat is conducted through the silica material of tubular member 322 to 
area 329 opposite surface 318. A second laser beam 333 from a laser 335 is 
directed through lens 334 to provide localized heat on the surface of 
tubular member 322 opposite surface 315 provides heat in the range of 
1400.degree. to 1700.degree. C. which is applied to tubular member 322 
adjacent the end of fiber 317. The heat in area 336 fuses the material of 
fiber 317 opposite surface 315 to the adjacent side of tubular member 322. 
A single laser beam can be used to sequentially unite the opposite sides 
of fiber 317 to adjacent portions of tubular member 322. The silica 
material within areas 329 and 336 are melted and fused together as shown 
in FIGS. 22-25. Laser beams 327 and 333 are generated with carbon dioxide 
(CO.sub.2) lasers 332 and 335. Other types of laser energy and heat 
sources can be used to unite the opposite portions of the end of fiber 317 
to the inside of tubular member 322. 
Probe 333 is made by providing an elongated optical fiber adapted to be 
coupled to a laser used to direct a laser beam or light along the fiber. 
The optical fiber has a silica fiber core enclosed within a fused silica 
cladding 319 and a sleeve 320 surrounded by a jacket 321. A cutter or 
similar tool is used to cut a V-shaped groove across the end of fiber 317 
to form surfaces 315 and 318. Each surface 315 and 318 has an angle of 37 
degrees relative to the longitudinal axis of fiber 317 to provide inclined 
surfaces 315 and 318. Surfaces 315 and 318 are polished with a 
diamond-tipped abrasive tool, carbon dioxide (CO.sub.2) laser, or excimer 
laser to provide a smooth and flat surface. A tubular member 322, having a 
closed convex end 323 and an air chamber 324, is provided to accommodate 
and support tubular member 322 and prevent separation of tubular member 
322 from fiber 317. The distal end of fiber 317 is inserted through the 
open end of tubular member 322 into air chamber 324. Tubular member 322 is 
then secured to sleeve 320 and jacket 321 with surfaces 315 and 318 spaced 
from the inside of closed end 323 of member 322. A first heat source 332, 
generates a carbon dioxide (CO.sub.2) laser beam 327, and is localized on 
the surface of the tubular member 322 opposite surface 318 to unite or 
fuse fiber 317 to member 322 in area 329 opposite surface 318. A second 
heat source 335 generates a laser beam 333 that is localized on the 
surface of tubular member 322 to unite the silica material of fiber 317 
with the adjacent silica material of tubular member 322. As seen in FIGS. 
23 and 25, fused areas 325 and 326 each have a circumferential length of 
about 100 degrees. Other circumferential or arcuate lengths of fused areas 
325 and 326 can be used to connect fiber 317 to member 322. The progress 
of the fusing process is monitored visually or by instrumentation. 
Referring to FIGS. 24 and 25, light or laser beam 330 generated by a laser 
axially propagates down fiber 317. When light 330 encounters a change in 
refractive index, it redirects a portion of the light energy indicated by 
arrows 331 and 336. The angles of polished surfaces 315 and 318 being 37 
degrees relative to the longitudinal axis of fiber 317 results in almost 
total internal reflection of light 330 as redirected light 331 and 336 at 
an angle of approximately 70 degrees relative to the longitudinal axis of 
fiber 317. Light 331 and 336 is efficiently redirected laterally through 
fiber 317, the fused areas 325 and 326, and member 322, being of the same 
silica materials, do not produce changes in the refractive indices and 
thereby do not produce reflected light nor secondary refractive light. 
Reflections that stem from multiple changes in the refractive indices in 
the exit path of the laser beam are eliminated. Probe 333 is a reliable 
means to efficiently deliver high energy laser light in opposite lateral 
directions that is essentially not wavelength selective. 
Referring to FIGS. 26-32, there is shown a third modification of the 
side-firing laser optical fiber probe of the invention, indicated 
generally at 413. Probe 413 has an elongated flexible optical fiber 417 
terminating in a recessed inclined cone-shaped surface 418. Fiber 417 has 
a silica fiber core surrounded with a doped fused silica cladding 419. 
Surface 418 has a generally recessed cone-shaped polished shape. Surface 
418 can be covered with a coating material, such as a gold or silver film 
or dielectric material. A diamond-tipped abrasive tool, a carbon dioxide 
(CO.sub.2) laser tightly focused or excimer laser can be used to polish 
surface 418. These polishing methods are examples of polishing technology 
for polishing surface 418. Other polishing procedures can be used to 
create the desired surface characteristics on surface 418. Surface 418 is 
inclined forwardly at an angle of 37 degrees relative to the longitudinal 
axis of fiber 417. Other angles can be used for surface 418. When the 
angle of surface 418 is 37 degrees, the reflected light will emerge at 
approximately 70 degrees in air with an associated divergence. A tubular 
layer of silica cladding 419 surrounds fiber 417 to protect the fiber and 
maintain the laser light within fiber 417. Cladding 419 is covered with a 
plastic sleeve 420 surrounded with a plastic jacket, such as jacket 21. A 
transparent capsule or tubular member 422 having a closed convex curved 
end 423 is located about the distal end of fiber 417 to enclose the distal 
end of fiber 417 within a gas chamber 424. The gas is air. The distal end 
of fiber 417 is surrounded by chamber 424 and spaced from the inside of 
end 423. Member 422 is a silica cylindrical tubular member made of silica 
material the same as or similar to the material of fiber 417. 
The distal end of fiber 417 is united at 425 to the inside annular wall of 
tubular member 422. The silica materials of fiber 417 and tubular member 
422 are fused with localized heat. As shown in FIG. 28, the heat required 
to cause the fusion of the silica materials of fiber 417 and tubular 
member 422 is supplied by a laser 432 which generates a laser beam 427. 
Laser beam 427 is directed through an optical lens 428 which concentrates 
the laser beam 427 on the surface of tubular member 422 opposite surface 
418. A second laser 435 generating a laser beam 433 is used to unite the 
silica material in area 436. One or more laser beams travelling around 
tubular member 422 can be used to unite annular portions of fiber 417 and 
tubular member 422 together. Alternatively, probe 413 can be rotated about 
its longitudinal axis whereby laser beams 427 and 433 unit adjacent 
annular portions of fiber 417 to tubular member 422. The silica material 
within annular areas 429 and 436 are melted and fused together as shown in 
FIGS. 30-33. Laser beams 427 and 433 are carbon dioxide (CO.sub.2) laser 
beams. Other types of laser energy and heat sources can be used to unite 
the end of fiber 417 to the inside of tubular member 422. 
Probe 433 is made by providing an elongated optical fiber adapted to be 
coupled to a laser used to direct a laser beam or light along the fiber. 
The optic fiber has a silica fiber core 417 enclosed within a fused silica 
cladding 419 and a plastic sleeve 420. A plastic jacket 421 covers sleeve 
420. A cone-shaped recess having a cone surface 418 is cut or drilled into 
the distal end of fiber 417. A laser generating a laser beam can be used 
to make the cone-shaped recess in the distal end of fiber 417. The 
cone-shaped surface 418 has an angle of 37 degrees relative to the 
longitudinal axis of fiber 417 to provide inclined cone surface 418. 
Surface 418 is polished with a diamond-tipped abrasive tool, carbon 
dioxide (CO.sub.2) laser, or excimer laser to provide a smooth and flat 
surface. 
A tubular member 422, having a closed end 423 and air chamber 424, is 
provided to accommodate and support the distal end of fiber 417. The 
distal end of fiber 417 is inserted through the open end of tubular member 
422 into air chamber 424. Tubular member 422 is then secured to sleeve 421 
with surface 418 spaced from the closed end 423 of member 422. Heat 
sources, such as carbon dioxide (CO.sub.2) laser beams from lasers 432 and 
435 are localized on the outer surface of tubular member 422 opposite 
surface 418 to unite or fuse fiber 417 to member 422 in area 429 opposite 
surface 418. As seen in FIGS. 31 and 33, fused area 425 has a 
circumferential length of 360 degrees. Probe 413 and laser beams 427 and 
433 can be rotated relative to each other to angularly unite fiber 417 
with tubular member 422. 
An alterative method of annularly fusing the distal end of fiber 417 to 
tubular member 422 is to provide a tubular member having an open distal 
end. Laser light from a laser is directed through the open end of the 
tubular member to annularly unite or fuse the distal end of the fiber 417 
to the inside wall of the tubular member. The laser light is also used to 
cut a generally cone-shaped recess in the distal end of the fiber 417 and 
providing a polished cone-shaped surface. Coating materials, such as metal 
films or dielectric materials, can be applied to the cone-shaped surface. 
The open end of the tubular member is closed by subjecting the distal end 
of the tubular member to heat from laser light generated by a laser. The 
progress of the fusing process is monitored visually or by 
instrumentation. 
Referring to FIGS. 32 and 33, light or laser beam 430 generated by a laser 
axially propagates down fiber 417. When light 430 encounters a change in 
refractive index, it redirects the light energy laterally of the 
longitudinal axis of fiber 417 indicated by arrows 431. The angle of 
polished surface 418 being 37 degrees relative to the longitudinal axis of 
fiber 417 results in almost total internal reflection of light 430 as 
redirected light 431 at an angle of approximately 70 degrees relative to 
the longitudinal axis of fiber 417. Light 431 is efficiently redirected 
laterally through the distal end of fiber 417, the fused area 425 and 
member 422. Light 431, as seen in FIG. 33, is directed laterally 360 
degrees around probe 413. Fiber 417, fused area 425 and member 422, being 
of the same silica materials, do not produce changes in the refractive 
indices and thereby do not produce reflected light nor secondary 
refractive light. Reflections that stem from multiple changes in the 
refractive indices in the exit path of the laser beam are eliminated. 
Probe 413 is a reliable means to efficiently deliver high energy laser 
light 360 degrees laterally of the probe that is essentially not 
wavelength selective. 
There have been shown and described several embodiments of the laser optic 
fiber probe and methods of making the probe of the invention. It is 
understood that modifications, changes in the structures, arrangement of 
structures, materials and methods of making the probe can be made by one 
skilled in the art without departing from the invention. The invention is 
defined in the following claims.