Abstract:
A display device and method of operating the display device. The display device comprising a support substrate, a plurality of light emitting resonators placed in a matrix on the support substrate forming a plurality of rows and columns of the light emitting resonators, a plurality of light waveguides positioned on the substrate such that each of the light emitting resonators is associated with an electro-coupling region with respect to one of the plurality of light waveguides, a deflection mechanism for causing relative movement between a portion of at least one of the plurality of light waveguides and the associated light emitting resonator so as to control when the light emitting resonator is in the electro-coupling region, and a light source associated with each of the plurality of light waveguides for transmitting a light along the plurality of light waveguides for selectively activating each of the light emitting resonators when positioned within the electro-coupling region.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   U.S. Ser. No. 11/096,032, filed concurrently herewith, of John P. Spoonhower, David Lynn Patton and Frank Pincelli, entitled “Visual Display With Electro-Optical Individual Pixel Addressing Architecture”; 
   U.S. Ser. No. 11/096,031, filed concurrently herewith, of John P. Spoonhower and David Lynn Patton, entitled “Polarized Light Emitting Source With An Electro-Optical Addressing Architecture”; and 
   U.S. Ser. No. 11/094,855, filed concurrently herewith, of John P. Spoonhower, and David Lynn Patton entitled “Placement Of Lumiphores Within A Light Emitting Resonator In A Visual Display With Electro-Optical Addressing Architecture”; 
   FIELD OF THE INVENTION 
   A flat panel visible display wherein optical waveguides and other thin film structures are used to distribute (address) excitation light to a patterned array of visible light emitting pixels. 
   BACKGROUND OF THE INVENTION 
   A flat panel display system is based on the generation of photo-luminescence within a light cavity structure. Optical power is delivered to the light emissive pixels in a controlled fashion through the use of optical waveguides and a novel addressing scheme employing Micro-Electro-Mechanical Systems (MEMS) devices. The energy efficiency of the display results from employing efficient, innovative photo-luminescent species in the emissive pixels and from an optical cavity architecture, which enhances the excitation processes operating inside the pixel. The present system is thin, light weight, power efficient and cost competitive to produce when compared to existing technologies. Further advantages realized by the present system include high readability in varying lighting conditions, high color gamut, viewing angle independence, size scalability without brightness and color quality sacrifice, rugged solid-state construction, vibration insensitivity and size independence. The present invention has potential applications in military, personal computing and digital HDTV systems, multi-media, medical and broadband imaging displays and large-screen display systems. Defense applications may range from full-color, high-resolution, see-through binocular displays to 60-inch diagonal digital command center displays. The new display system employs the physical phenomena of photo-luminescence in a flat-panel display system. 
   Previously, Newsome disclosed the use of upconverting phosphors and optical matrix addressing scheme to produce a visible display in U.S. Pat. No. 6,028,977. Upconverting phosphors are excited by infrared light; this method of visible light generation is typically less efficient than downconversion (luminescent) methods like direct fluorescence or phosphorescence, to produce visible light. Furthermore, the present invention differs from the prior art in that a different addressing scheme is employed to activate light emission from a particular emissive pixel. The method and device disclosed herein does not require that two optical waveguides intersect at each light emissive pixel. Furthermore, novel optical cavity structures, in the form of optical light emitting resonators, are disclosed for the emissive pixels in the present invention. 
   Additionally, in U.S. Patent Application Publication US2002/0003928A1, Bischel et al. discloses a number of structures for coupling light from the optical waveguide to a radiating pixel element. The use of reflective structures to redirect some of the excitation energy to the emissive medium is disclosed. In the present invention, we disclose the use of novel optical cavity structures, in the form of ring or disk resonators, the resonators themselves modified to affect the emission of visible light. 
   The use of such resonators further allows for a noyel method of control of the emission intensity, through the use of Micro-Electro-Mechanical Systems (MEMS) devices to alter the degree of power coupling between the light power delivering waveguide and the emissive resonator pixel. Such means have been disclosed in control of the power coupling to opto-electronic filters for telecommunications applications. In this case, the control function is used to tune the filter. Control over the power coupling is described in “A MEMS-Actuated Tunable Microdisk Resonator”, by Ming-Chang M. Lee and Ming C. Wu, paper MC3, 2003 IEEE/LEOS International Conference on Optical MEMS, 18-21 Aug. 2003. 
   SUMMARY OF THE INVENTION 
   In accordance with one aspect of the present invention there is provided a display device, comprising: 
   a. a support substrate; 
   b. a plurality of light emitting resonators placed in a matrix on the support substrate forming a plurality of rows and columns of the light emitting resonators; 
   c. a plurality of light waveguides positioned on the substrate such that each of the light emitting resonators is associated with an electro-coupling region with respect with to one of the plurality of light waveguides; 
   d. a deflection mechanism for causing relative movement between a portion of at least one of the plurality of light waveguides and the associated light emitting resonator so as to control when the light emitting resonator is in the electro-coupling region; and 
   e. a light source associated with each of the plurality of light waveguides for transmitting a light along the plurality of light waveguides for selectively activating each of the light emitting resonators when positioned within the electro-coupling region. 
   In accordance with another aspect of the present invention there is provided a method for controlling visible light emitting from a display device having a plurality of light emitting resonators placed in a pattern forming a plurality of rows and columns and a plurality of wave light guides positioned so that each of the light emitting resonators is positioned adjacent one of the plurality of wave light guides comprising the steps of: 
   a) providing a light source associated with each of the plurality of light waveguides for transmitting a light along the associated light waveguide; 
   a) providing deflection mechanism for causing relative movement between a portion of at least one of the plurality of light waveguides and the associated light emitting resonator so as to control when the light emitting resonator is in the electro-coupling region; 
   b) selectively controlling emission of visible light from the plurality of light emitting resonators by controlling the deflection mechanism and light source such that when the light emitting resonator in the electro-coupling region and a light is transmitted along the associated light waveguide the emission of visible light will occur. 
   These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims and by reference to the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, features, and advantages of the present invention will become more apparent when taken in conjunction with the following description and drawings wherein identical reference numerals have been used, where possible, to designate identical features that are common to the figures, and wherein: 
       FIG. 1  is a schematic top view of an optical flat panel display made in accordance with the present invention; 
       FIGS. 2A ,  2 B and  2 C are enlarged top plan views of red light, green light and blue light emitting resonators for a color display made in accordance with the present invention; 
       FIG. 3  is an enlarged cross-sectional view of the optical waveguide as taken along line  3 - 3  of  FIG. 2 ; 
       FIG. 4  is an enlarged cross-sectional schematic view of the optical waveguide showing the electrode geometry and electrostatic forces; 
       FIG. 5  is an enlarged perspective view of a portion of the display of  FIG. 1  showing a single ring resonator, single associated optical waveguide and electrodes; 
       FIGS. 6A , B and C are enlarged cross-sectional views of the display of  FIG. 5  taken along line  6 - 6  of  FIG. 5 , which shows the location of a MEMS device used to control the pixel intensity at various intensity positions; 
       FIG. 7  is an enlarged cross-sectional view of the waveguide and resonator elements showing an alternative embodiment for the light-emissive resonator; and 
       FIG. 8  is an enlarged top plan view showing an alternative resonator embodiment in the form of a disk. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 1-2  there is illustrated a photo-luminescent display  5  system made in accordance with the present invention. The display system functions by converting excitation light to emitted, visible light. In the embodiment illustrated, each pixel  10  in display  5  is comprised of one or more sub-pixels; sub-pixels are typically comprised of a red sub-pixel  11 , a green sub-pixel  12 , and a blue sub-pixel  13 , as shown in  FIG. 2 . Colors other than red, green, and blue are caused by the admixture of these primary colors thus controlling the intensity of which the individual sub-pixels adjusts both the brightness and color of a pixel  10 . Those skilled in the art understand that other primary color selections are possible and will lead to a full color display. Color generation in the display is a consequence of the mixing of multiple-wavelength light emissions by the viewer. This mixing is accomplished by the viewer&#39;s integration of spatially distinct, differing wavelength light emissions from separate sub-pixels that are below the spatial resolution limit of the viewer&#39;s eye. Typically a color display has red, green, and blue separate and distinct sub-pixels, comprising a single variable color pixel. Monochrome displays may be produced by the use of a single color pixel  10  or sub-pixel  11 ,  12 ,  13 , or by constructing a single pixel capable of emitting “white” light. The spectral characteristics of a monochrome display pixel will be determined by the choice of lumiphore or combination of lumiphores. White light generation can be accomplished through the use of multiple doping schemes for the light emitting resonator  30  as described by Hatwar and Young in U.S. Pat. No. 6,727,644B2. Photo-luminescence is used to produce the separate wavelength emission from each pixel (or subpixel) element. The photo-luminescence may be a result of a number of physically different processes including, multi-step, photonic up-conversion processes and the subsequent radiative emission process, direct optical absorption and the subsequent radiative emission process, or optical absorption followed by one or more energy transfer steps, and finally, the subsequent radiative emission process. Use of combinations of these processes may also be considered to be within the scope of this invention. 
     FIG. 1  is schematic top view of an optical flat panel display  5  made in accordance with the present invention. The display  5  contains an array  7  of light emitters comprised of a matrix of pixels  10  each having a light emitting resonator  30  (shown in  FIGS. 2A , B, and C) located at each intersection of an optical row waveguide  25  and column electrodes  28 . A power source  22  is used to activate the light source array  15 . The light source array  15  provides optical power or light  20 , used to excite the photo-luminescent process in each pixel  10 . Typical light source array elements  17  may be diode lasers, infrared laser, light emitting diodes (LEDs), and the like. These may be coherent or incoherent light sources. These light sources may be visible, ultraviolet, or infrared light sources. There may be a one-to-one correspondence between the light source array element  17 , and an optical row waveguide  25 , or alternatively, there may be a single light source array element  17  multiplexed onto a number of optical row waveguides  25 , through the use of an optical switch to redirect the light  20  output from the single light source array element  17 . 
   A principal component of the photo-luminescent flat panel display system  5  is the optical row waveguide  25 , also known as a dielectric waveguide. Two key functions are provided by the waveguides  25 . They confine and guide the optical power to the pixel  10 . Several channel waveguide structures have been illustrated in U.S. Pat. No. 6,028,977. The optical waveguides must be restricted to TM and TE propagation modes. TM and TE mode means that optical field orientation is perpendicular to the direction of propagation. Dielectric waveguides confining the optical signal in this manner are called channel waveguides. The buried channel and embedded strip guides are applicable to the proposed display technology. Each waveguide consists of a combination of cladding and core layer. These layers are fabricated on either a glass-based or polymer-based substrate. The core has a refractive index greater than the cladding layer. The core guides the optical power past the resonator in the absence of power coupling. With the appropriate adjustment of the distance between the optical row waveguide  25  and the light emitting resonator  30 , power is coupled into the light emitting resonator  30 . At the light emitting resonator  30  the coupled optical light power drives the resonator materials into a luminescent state. The waveguides  25  and resonators  30  can be fabricated using a variety of conventional techniques including microelectronic techniques like lithography. These methods are described, for example, in “High-Finesse Laterally Coupled Single-Mode Benzocyclobutene Microring Resonators” by W. -Y. Chen, R. Grover, T. A. Ibrahim, V. Van, W. N. Herman, and P. -T. Ho, IEEE Photonics Technology Letters, 16(2), p. 470. Other low-cost techniques for the fabrication of polymer waveguides can be used such as imprinting, and the like. Nano-imprinting methods have been described in “Polymer microring resonators fabricated by nanoimprint technique” by Chung-yen Chao and L. Jay Gao, J. Vac. Sci. Technol. B 20(6), p. 2862. Photobleaching of polymeric materials as a fabrication method has been described by Joyce K. S. Poon, Yanyi Huang, George T. Paloczi, and Amnon Yariv, in “Wide-range tuning of polymer microring resonators by the photobleaching of CLD-1 chromophores” by, Optics Letters 29(22), p. 2584. This is an effective method for post fabrication treatment of optical micro-resonators. A wide variety of polymer materials are useful in this and similar applications. Theses can include fluorinated polymers, polymethylacrylate, liquid crystal polymers, and conductive polymers such as polyethylene dioxythiophene, polyvinyl alcohol, and the like. These materials and additionally those in the class of liquid crystal polymers are suitable for this application (see “Liquid Crystal Polymer (LCP) for MEMs”, by X. Wang et. al., J. Micromech. MicroEng, 13, (2003), p. 628-633.) This list is not intended to be all inclusive of the materials that may be employed for this application. 
   Excitation of the light emitting resonator  30  (shown in  FIGS. 2A , B, and C) by the row waveguide  25  under the control of the column voltage source  18  and column electrodes  28  causes the light emitting resonator  30  to emit visible light. The excitation of the light emitting resonator  30  is caused by optical pumping action of the light  20  shown in  FIG. 1  from a row light source array element  17  through the row waveguide  25  and controlling voltage to the column electrodes  28  by multiplex controller  19  from a column voltage source  18 . The excitation process is a coordinated row-column, electrically activated, optical pumping process called electro-optical addressing. Those skilled in the art know that the roles of columns and rows are fully interchangeable without affecting the performance of this display  5 . 
   Now referring to  FIG. 2A , electro-optical addressing is defined as a method for controlling an array  7  (not shown) of light emitting resonators  30  that form the optical flat panel display  5  (see  FIG. 1 ). In  FIG. 2A , a pixel  10  comprised of three sub-pixels,  11 ,  12 , and  13  is shown. In electro-optical addressing, the selection of a particular pixel that appears to be light emitting is accomplished by the specific combination of excitation of light in a particular optical row waveguide  25 , and voltage applied to a particular set of column electrodes  28 . 
   The light emitting resonator  30  is excited into a photo-luminescent state through the absorption of light  20  as a result of the close proximity to the row waveguides  25 . The physics of the coupling of energy between the resonator  30  and the optical row waveguide  25  is well known in the art. It is known to depend critically upon the optical path length between the row waveguide  25  and the light emitting resonator  30 ; it can therefore be controlled by the distance (h shown in  FIGS. 6A and 6B ) separating the two structures or by various methods of controlling the index of refraction. Typical methods for control of the index of refraction include heat, light, and electrical means; these are well known. These methods correspond respectively to the thermo-optic, photorefractive, and electro-optic methods. The invention disclosed herein makes use of control of the distance parameter via a MEMS device to control the energy coupling, and thus affect the intensity of photo-luminescent light generated in the pixel  10 . In an example, the light emitting resonator  30  is composed of a light transmissive material but incorporating (doped with) a light emitting photo-luminescent species. The base material (the material excluding the photo-luminescent species or dopant) for the light emitting resonator may be the same or different from the optical row waveguide  25  material. Typical base materials can include glasses, semiconductors, or polymers. 
   Photo-luminescent species or dopants can include various fluorophores, or phosphors including up-converting phosphors. The selection of a particular dopant or dopants will primarily determine the emission spectrum of a particular light emitting resonator  30 . These lumiphores (fluorophores or phosphors) may be inorganic materials or organic materials. The light emitting resonator  30  can include a combination of dopants that cause it to respond to the electro-optic addressing by emitting visible radiation. Dopant or dopants include the rare earth and transition metal ions either singly or in combinations, organic dyes, light emitting polymers, or materials used to make Organic Light Emitting Diodes (OLEDs). Additionally, lumiphores can include such highly luminescent materials such as inorganic chemical quantum dots, such as nano-sized CdSe or CdTe, or organic nano-structured materials such as the fluorescent silica-based nanoparticles disclosed in U.S. Patent Application Publication US 2004/0101822 by Wiesner and Ow. The use of such materials is known in the art to produce highly luminescent materials. Single rare earth dopants that can be used are erbium (Er), holmium, thulium, praseodymium, neodymium (Nd) and ytterbium. Some rare-earth co-dopant combinations include ytterbium, erbium, ytterbium, thulium and thulium: praseodymium. Single transition metal dopants are chromium (Cr), thallium (Tl), manganese (Mn), vanadium (V), iron (Fe), cobalt (Co) and nickel (Ni). Other transition metal co-dopant combinations include Cr:Nd and Cr:Er. The up-conversion process has been demonstrated in several transparent fluoride crystals and glasses doped with a variety of rare-earth ions. In particular, CaF 2  doped with Er 3+ . In this instance, infrared up-conversion of the Er3+ ion can be caused to emit two different colors: red (650 nm) and green (550 nm). The emission of the system is spontaneous and isotropic with respect to direction. Organic fluorophores can include dyes such as Rhodamine B, and the like. Such dyes are well known having been applied to the fabrication of organic dye lasers for many years. The preferred organic material for the light emitting resonator  30  is a small-molecular weight organic host-dopant combination typically deposited by high-vacuum thermal evaporation. It is also preferred that the host materials used in the present invention are selected such that they have sufficient absorption of the excitation light  20  and are able to transfer a large percentage of their excitation energy to a dopant material via Förster energy transfer. Those skilled in the art are familiar with the concept of Förster energy transfer, which involves a radiationless transfer of energy between the host and dopant molecules. An example of a useful host-dopant combination for red-emitting lasers is aluminum tris(8-hydroxyquinoline) (Alq) as the host and [4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran] (DCJTB) as the dopant (at a volume fraction of 1%). Other host-dopant combinations can be used for other wavelength emissions. For example, in the green a useful combination is Alq as the host and [10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H,5H,11H-[1]Benzopyrano[6,7,8-ij]quinolizin-11-one] (C545T) as the dopant (at a volume fraction of 0.5%). Other organic light emitting materials can be polymeric substances, e.g., polyphenylenevinylene derivatives, dialkoxy-polyphenylenevinylenes, poly-para-phenylene derivatives, and polyfluorene derivatives, as taught by Wolk et al. in commonly assigned U.S. Pat. No. 6,194,119B1 and references therein. 
   Electro-optical addressing employs the optical row waveguide  25  to deliver light  20  to a selected light emitting resonator  30 . The light emitting resonator  30  is the basic building block of the optical flat panel display  5 . Referring now to  FIGS. 2A ,  2 B, and  2 C, an enlarged top view of a red light  41 , green light  42  and blue light  43  light emitting resonator  30  respectively, is illustrated respectively in these figures. Using the red light  41 , green light  42  and blue light  43  light emitting resonators to create red  11 , green  12 , and blue  13  pixels, a full color optical flat panel display  5  can be formed. The wavelength of the emission of the red  41 , green  42  and blue  43  light is controlled by the type of material used in forming the light emitting resonators  30 . Selection of a particular pixel  10  or sub-pixel ( 11 - 13 ) is based upon the use of a MEMS device to alter the distance and affect the degree of power transfer of light  20  to the light emitting resonator  30 . Note that in each instance, light  20  is directed within an appropriate optical row waveguide  25  to excite a particular light emitting resonator  30 . Through the combination of excitation specific optical row waveguide with light  20  and excitation of a specific MEMS device, controlled by the column electrodes  28 , a particular pixel  10  (subpixel) is excited. The light emitting resonator  30  may take the form of a micro-ring or a micro-disk. These forms are shown in  FIGS. 2 and 5 , respectively. Note that in order for the light emitting resonator  30  to produce sufficient light to be viewable, the resonator  30  must be fabricated in a manner so that it is ‘leaky”; there are a number of methods to accomplish this lowering of the cavity Q, including but not limited to increasing the surface roughness of the resonator cavity surface. Additionally, one could lower the refractive index of the material comprising the light emitting resonator  30 . 
   The display substrate or support  45  (see  FIG. 3 ) can be constructed of either a silicon, glass or a polymer-based substrate material. A number of glass and polymer substrate materials are either commercially available or readily fabricated for this application. Such glass materials include: silicates, germanium oxide, zirconium fluoride, barium fluoride, strontium fluoride, lithium fluoride, and yttrium aluminum garnet glasses. A schematic of an enlarged cross-sectional view of the optical flat panel display  5  taken along the line  3 - 3  of  FIG. 2  is shown in  FIG. 3 . The column electrodes  28  are not shown for simplicity. On a substrate  45  is formed a layer  35  containing the optical row waveguide  25  and the light emitting resonator. For such a buried-channel waveguide structure it is imperative that the refractive index of optical row waveguide  25  (the core) be greater than the surrounding materials, in this instance the layer  35 . The layer  35  acts as the cladding region in this embodiment. An optional layer  32  is shown; this may be of a relatively lower index material in order to better optically isolate the optical row waveguide  25 . A top layer  52  is provided on the top surface  47  of layer  35  for protection of the underlying structures. In the case of  FIG. 3  the entire structure is shown surrounded by air  55 . 
   Integrated semiconductor waveguide optics and microcavities have raised considerable interest for a wide range of applications, particularly for telecommunications applications. The invention disclosed herein applies this technology to electronic displays. As stated previously, the energy exchange between cavities and waveguides is strongly dependent on the spatial distance. Controlling the distance between waveguides and microcavities is a practical method to manipulate the power coupling and hence the brightness of a pixel  10  or sub-pixel ( 11 - 13 ). 
   An ideal resonator or cavity has characteristics of high quality factor (which is the ratio of stored energy to energy loss per cycle) and small mode volume. Dielectric micro-sphere and micro-toroid resonators have demonstrated high quality factors. Micro-cavities possess potential to construct optical resonators with high quality factor and ultra-small mode volume due to high index-contrast confinement. Small mode volume enables small pixel  10  or sub-pixel ( 11 - 13 ) dimensions, consistent with the requirements of a high resolution display. A MEMS device structure for affecting the amount of light  20  coupled into a light emitting resonator  30  is shown in  FIG. 4 .  FIG. 4  is an enlarged cross-sectional view of the optical waveguide showing the electrode geometry, field lines  46 , and resulting downward electrostatic force  44  for affecting the power coupling change. MEMS actuators using electrostatic forces in this instance, move a waveguide to change the distance h e , shown in  FIG. 6A  between a resonator and the optical row waveguide  25 , resulting in a wide tunable range of power coupling ratio by several orders of magnitude which is difficult to achieve by other methods. Based on this mechanism, the micro-disk/waveguide system can be dynamically operated in the under-coupled, critically-coupled and over-coupled condition. 
   In high-Q micro-resonators, varying the gap spacing or distance h, between the waveguide and the micro-disk or micro-ring resonator by simply a fraction of a micron leads to a very significant change in the power transfer to the light emitting resonator  30  from the optical row waveguide  25 .  FIG. 5  is an enlarged perspective view of the display of  FIG. 1  showing a light emitting ring resonator  30 ; optical waveguide  25 , and electrodes  28 . As shown in  FIG. 5 , a suspended waveguide is placed in close proximity to the micro-ring or micro-toroid light emitting resonator  30 . The initial gap (not shown) (˜1 μm wide) is large so there is no coupling between the waveguide and the resonator. Referring to  FIG. 5 , the suspended optical row waveguide  25  can be pulled towards the micro-ring resonator by four electrostatic gap-closing actuators, the electrodes  28 . Therefore, the coupling coefficient can be varied by applied voltage. For high index-contrast waveguides, the coupling coefficient is very sensitive to the critical distance. 1-um displacement can achieve a wide tuning range in power coupling ratio, which is more than five orders of magnitude. Typically, the radius of micro-ring resonator is 10 μm and the width of waveguide is 0.7 μm. But these sizes may vary depending upon the display type and application. In  FIG. 5  the optical waveguide  25  is shown displaced downward so as to affect a maximum power transfer to the light emitting resonator  30 . 
     FIG. 6A  is an enlarged cross-sectional view of the display of  FIG. 5 , which shows the location of a MEMS device used to control the pixel intensity. The area surrounding the optical row waveguide  25  and the light emitting ring resonator  30  has been etched back to expose the top surfaces  48  to air  55 . The optical row waveguide  25  is aligned to the edge of the light emitting resonator  30  and vertically displaced to preclude a high degree of coupling. The waveguide  25  is electrically grounded and actuated by a pair of electrodes  28  at the two ends, which forms an electro-coupling region  58 . Due to the electrostatic force, the waveguide is pulled downward toward the light emitting resonator  30 , resulting in the decreased gap-spacing h. The optical row waveguide  25  is shown in the rest position d in  FIG. 6A . In  FIG. 6A , the distance between the optical row waveguide  25  and the light emitting ring resonator  30  is large; coupling of light into the light emitting resonator  30  is precluded and there is no light emission from the pixel. 
   Initially, in the absence of the application of the control voltage, the optical row waveguide  25  is separated from the light emitting resonator by a distance significantly greater than the critical distance “h c ”  31  (see  FIG. 6C ) and hence there is no light emission from the light emitting resonator  30 . In  FIG. 6B , the vertical distance d″ is shown where there exists a degree of coupling between the optical row waveguide  25  and the light emitting ring resonator  30 , and hence light emission from the pixel occurs. By varying the distance d′, the intensity of the light emission from the pixel can be varied in a controllable manner. In  FIG. 6C , the distance d′ is shown that corresponds to the displacement of the optical row waveguide  25  necessary to place the optical row waveguide  25  at the critical coupling distance h c  and thereby optimize power coupling. This configuration will produce the maximum emitted light intensity from the pixel. Note that light emitting resonator is shown with a roughened surface  60 ; this will be discussed below. The optical row waveguide can be fabricated from silicon appropriately doped to provide electrical conductivity. Alternatively, the optical row waveguide can be fabricated from other optically transparent conductive materials such as polymers that meet the optical index of refraction requirement disclosed above. 
   In the embodiment shown in  FIG. 6C , the light emitting resonator  30  is shown spaced the critical distance  31 , h c  from the optical row waveguide  25 . Excitation light  20  is emitted from top roughened surface  60  of the light emitting resonator  30 , which causes the light emitting resonator to leak light and become visible to a viewer. As shown in  FIG. 6C , a light emitting layer  49  is placed within the light emitting resonator. This layer  49  contains photo-luminescent species or lumiphores  65  that absorb the pump or excitation light  20  and via the luminescence processes discussed above, produce the visible light directed to the viewer. The wavelength of the light produced in the emitting layer  49  is determined by the material composition as previously disclosed. The light emitting layer  49  may be formed on the top surface of the light emitting resonator  30  as well as placed within the internal structure of the light emitting resonator as is shown in  FIG. 6C .  FIG. 6C  shows the emitting layer  49  displaced vertically from the bottom surface  39  of light emitting resonator  30 . 
     FIG. 7  is an enlarged cross-sectional view of the resonator elements showing an alternative embodiment for the light-emissive resonator  30 . In this embodiment the lumiphores  65  are shown uniformly distributed within the light emitting resonator  30 . 
     FIG. 8  is an enlarged top plan view showing an alternative resonator embodiment in the form of a disk. The critical distance “h c ”  31  is shown as well as the light emitting disk  67  resonator. A number of structures have been demonstrated for the resonator element including ring, disk, elliptical and racetrack or oval structures. The coupling of optical power into such structures is well known to those skilled in the art. The use of such structures as light emitting resonators is considered within the scope of this invention. 
   The invention has been described with reference to a preferred embodiment however, it will be appreciated that variations and modifications can be affected by a person of ordinary skill in the art without departing from the scope of the invention. In particular, it is well known in the art that the optical row waveguide  25  can be placed adjacent to the light emitting resonator  30  in the same horizontal plane, and tuned for power transfer by affecting a lateral, that is in-plane or horizontal displacement, rather than the vertical displacements depicted above. Additionally, it may be advantageous to place the optical row waveguide  25  above the light emitting resonator  30  adjacent to the periphery of the light emitting resonator  30 . In this latter case the electro-coupling region  58  would be placed vertically above the edge of the light emitting resonator  30  and power transfer affected by a vertical displacement of the optical row waveguide  25  relative to the top surface of the light emitting resonator  30 . Many other such variations are possible and considered within the scope of this invention. 
   PARTS LIST 
   
       
         5  display 
         7  array 
         10  pixel 
         11  red sub-pixel 
         12  green sub-pixel 
         13  blue sub-pixel 
         15  light source array 
         17  light source array element 
         18  column voltage source 
         19  multiplex controller 
         20  light 
         22  power source 
         25  row waveguide 
         28  column electrodes 
         30  light emitting resonator 
         31  critical distance 
         32  optional layer 
         35  layer 
         39  bottom surface of light emitting resonator 
         41  red light 
         42  green light 
         43  blue light 
         44  force 
         45  support 
         46  field lines 
         47  top surface 
         48  top surface 
         49  emitting layer 
         52  top layer 
         55  air 
         58  electro-coupling region 
         60  roughened surface 
         65  lumiphores 
         67  light emitting resonator disk