Abstract:
The present invention includes a system, apparatus and method for generating a three-dimensional image, the system comprising: a medium comprising a optical molecular switch molecule, wherein the optical molecular switch molecule has a non-fluorescent state and a fluorescent state, wherein at one wavelength of optical excitation the molecule has a first state, and at a second state the molecule fluoresces a second wavelength of excitation; and at least a first light source and a second light source into the medium, wherein light emitted by the at least first and second light sources are directed to contact the optical molecular switch molecule, e.g., scanning, weaving, diagonally or other pattern; wherein the optical molecular switch molecule is converted into a fluorescent “on state” by irradiation from the first light source, and the second light causes the optical molecular switch to emit light.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application Ser. No. 62/239,352, filed Oct. 9, 2015, U.S. Provisional Application Ser. No. 62/293,128, filed Feb. 9, 2016, and U.S. Provisional Application Ser. No. 62/378,367, filed Aug. 23, 2016 the entire contents of each are incorporated herein by reference. 
     
    
     TECHNICAL FIELD OF THE INVENTION 
       [0002]    The present invention relates in general to the field of displays, and more particularly, to a system and method for a three-dimensional optical switch display (OSD) device. 
       STATEMENT OF FEDERALLY FUNDED RESEARCH 
       [0003]    None. 
       BACKGROUND OF THE INVENTION 
       [0004]    Without limiting the scope of the invention, its background is described in connection with optical switching. 
         [0005]    One example is taught in U.S. Patent Application Publication No. 2004/0227694, filed by Sun and Liu, which discloses a method for a three-dimensional image display using laser induced fluorescence (LIF) of nanoparticles and molecules in a transparent medium. These applicants teach the use of upconversion wherein the stepwise absorbance of two photons from independent laser beams is used to generate a three dimensional image. 
         [0006]    Yet another example is found in U.S. Patent Application Publication No. 2015/0029315, filed by Refai, et al., which discloses a system for an ultra high-resolution three-dimensional display. Briefly, an image is generated from two beams of electromagnetic energy. A first wavelength is used to generate an image slice trough a chamber and a second beam is shaped with a line generator across a different axis to generate a three dimensional image. 
         [0007]    Yet another example is found in U.S. Pat. Nos. 3,609,706 and 3,609,707, which disclose a photochromic dye based volumetric three-dimensional display that uses 1′,3′,3′-trimethyl-6-nitrospiro(2H-1-benzopyran-2,2′-indoline as a photochromic material. 
       SUMMARY OF THE INVENTION 
       [0008]    In one embodiment, the present invention includes an apparatus for generating a three-dimensional image, the system comprising: a medium comprising an optical molecular switch molecule, wherein the optical molecular switch molecule has a non-fluorescent state and a fluorescent state, wherein at one wavelength of optical excitation, the molecule has a first state and at a second state the optical molecular switch molecule fluoresces at a second wavelength of excitation; and at least a first light source and a second light source into the medium, wherein light emitted by the at least first and second light sources are directed to contact the optical molecular switch molecule; wherein the optical molecular switch molecule is converted into a fluorescent “on state” by irradiation from the first light source, and when the second light source irradiates the optical molecular switch molecule in the “on state” the optical molecular switch molecule emits light. In one aspect, when the first and the second light source intersect the optical molecular switch molecule excites and releases light. In another aspect, the first or the second light source is a pulsed laser thereby to produce an improved voxel to background emission. In another aspect, the first and the second light source scan across the medium, wherein the optical molecular switch molecule that excite and emit light in the medium create the three dimensional image. In another aspect, the molecule is selected from at least one of an acridine, an anthracene, an arylmethine, a cyanin, a coumarin, an oxacine, an oxadiazole, a naphthalene, a pyrene, a squaraine, a tetrapyrrole, a xanthene, a spirhodamine, spirolactam rhodamine, or other common fluorescent, phosphorescent, long-lifetime luminescent, or chemiluminescent scaffolds, or derivatives thereof. In another aspect, the optical molecular switch molecule is attached to the medium. In another aspect, the light source can be a laser. In another aspect, the medium is liquid, solid, a liquigel, organic, inorganic, thixotropic, a crystal, a glass, a gel, a polymer, a gas, and combinations thereof. In another aspect, the light sources are selected to match the wavelength of excitation of the optical molecular switch molecule. In another aspect, the optical molecular switch molecule is a protein. In another aspect, the optical molecular switch molecule is a green fluorescent protein, cyan fluorescent protein, yellow fluorescent protein, red fluorescent protein, gold fluorescent protein and combinations thereof. In another aspect, the optical molecular switch molecule is a saturation dye, an acceptor fluorophore, a donor fluorophore, and combinations thereof. In another aspect, the optical molecular switch molecule is capable of energy transfer selected from fluorescence resonance energy transfer (FRET), through-bond energy transfer (TBET), or fluorescence resonance energy transfer (FRET) with a molecular-beacon. In another aspect, at least three optical molecular switch molecules are selected to provide at least three different colors that provide for color images. In another aspect, the three dimensional image can be viewed without glasses or tricking the brain to appear three-dimensional. In another aspect, the three dimensional image is volumetric. In another aspect, the first, the second or both light sources are lasers. In one aspect, the optical molecular switch molecule is resuspended in a solvent or a base selected from at least one of dioxane, tetrahydrofuran, acetone, methanol, ethanol, isopropanol, water, diisopropyl ethylamine, pyridine, carbonate, or bicarbonate. In another aspect, each of the first light source or the second light source projects a three-dimensional images by rapid scanning of the first or second light source, and the other light source is synchronized with a changing patterned of light to form a three dimensional image in the medium. In another aspect, each of the first light source or the second light source displays a three-dimensional image by projecting light into a woven pattern into the medium. In another aspect, each of the first light source or the second light source displays a three-dimensional image by projecting light into a diagonal pattern into the medium. In another aspect, an agent that filters stray light is provided in the medium or a surface of a vessel that contains the medium. In another aspect, an angle formed between the light emitted from the first light source and the light emitted by the second light sources is at an angle other than 90 degrees. In another aspect, the first light source is a UV projector with a short pass filter, and the second light source uses a long pass filter before a camera. In another aspect, the short pass filter is a 395 nm filter, and the long pass filter is at least one of a 515, a 550, or a 590 nm filter. 
         [0009]    In another embodiment, the present invention includes a method of generating a three dimensional image comprising: providing a medium comprising a optical molecular switch molecule, wherein the optical molecular switch molecule has a non-fluorescent state and a fluorescent state, wherein at one wavelength of optical excitation the molecule has a first state and at a second state the molecule fluoresces a second wavelength of excitation; and directing at least a first light source and a second light source into the medium, wherein light emitted by the at least first and second light source are directed to contact the optical molecular switch molecule in the medium; wherein the optical molecular switch molecule is converted into a fluorescent “on state” by irradiation from the first light source, and when the second light source irradiates the optical molecular switch molecule in the “on state” the optical molecular switch molecule emits light. In one aspect, the light source can be a laser. In another aspect, when the first and the second light source intersect the optical molecular switch molecule excites and releases light. In another aspect, the first or the second light source is a pulsed laser thereby to produce an improved voxel to background emission. In another aspect, the first and the second light source scan across the medium, wherein the optical molecular switch molecule that excite and emit light in the medium create the three dimensional image. In another aspect, the molecule is selected from at least one of an acridine, an anthracene, an arylmethine, a cyanin, a coumarin, an oxacine, an oxadiazole, a naphthalene, a pyrene, a squaraine, a tetrapyrrole, a xanthene, a spirhodamine, spirolactam rhodamine, or other common fluorescent, phosphorescent, long-lifetime or chemiluminescent scaffolds, or derivatives thereof. In another aspect, the optical molecular switch molecule is attached to the medium. In another aspect, the medium is liquid, solid, a liquigel, organic, inorganic, thixotropic, a crystal, a glass, a gel, a polymer, a gas, and combinations thereof. In another aspect, the light sources are selected to match the wavelength of excitation of the optical molecular switch molecule. In another aspect, the optical molecular switch molecule is a protein. In another aspect, the optical molecular switch molecule is a green fluorescent protein, cyan fluorescent protein, yellow fluorescent protein, red fluorescent protein, gold fluorescent protein and combinations thereof. In another aspect, the optical molecular switch molecule is a saturation dye, an acceptor fluorophore, a donor fluorophore, and combinations thereof. In another aspect, the optical molecular switch molecule is capable of energy transfer selected from fluorescence resonance energy transfer (FRET), through-bond energy transfer (TBET), or fluorescence resonance energy transfer (FRET) with a molecular-beacon. In another aspect, at least three optical molecular switch molecules are selected to provide at least three different colors that provide for color images. In another aspect, the three dimensional image can be viewed without glasses or tricking the brain to appear three-dimensional. In another aspect, the three dimensional image is volumetric. In another aspect, the first, the second or both light sources are lasers. In one aspect, the optical molecular switch molecule is resuspended in a solvent or a base selected from at least one of dioxane, tetrahydrofuran, acetone, methanol, ethanol, isopropanol, water, diisopropyl ethylamine, carbonate, or bicarbonate. In another aspect, each of the first light source or the second light source projects a three-dimensional images by rapid scanning of the first or second light source, and the other light source is synchronized with a changing patterned of light to form a three dimensional image in the medium. In another aspect, each of the first light source or the second light source displays a three-dimensional image by projecting light into a woven pattern into the medium. In another aspect, each of the first light source or the second light source displays a three-dimensional image by projecting light into a diagonal pattern into the medium. In another aspect, an agent that filters stray light is provided in the medium or a surface of a vessel that contains the medium. In another aspect, an angle formed between the light emitted from the first light source and the light emitted by the second light sources is at an angle other than 90 degrees. In another aspect, the first light source is a UV projector with a short pass filter, and the second light source uses a long pass filter before a camera. In another aspect, the short pass filter is a 395 nm filter, and the long pass filter is at least one of a 515, a 550, or a 590 nm filter. 
         [0010]    In yet another embodiment, the present invention includes a system displaying images in three dimensions comprising: an imaging system comprising: a medium comprising a optical molecular switch molecule, wherein the optical molecular switch molecule has a non-fluorescent state and a fluorescent state, wherein at one wavelength of optical excitation the molecule has a first state and at a second state the molecule fluoresces a second wavelength of excitation; at least a first laser and a second light source in optical communication with the medium, wherein light emitted by the at least first and second light sources are directed to contact the optical molecular switch molecule at a specific location in the medium; a memory, configured to store a representation of the three dimensional image; and a processor, operably coupled to the memory and the first light source and the second light source, wherein the processor is configured to direct the first and the second light source into the medium to convert the optical molecular switch molecule into a fluorescent “on state” by irradiation from the first light source, and when the second light source irradiates the optical molecular switch molecule in the “on state” the optical molecular switch molecule emits light at the specific location in the medium. In one aspect, when the first and the second light source intersect the optical molecular switch molecule excites and releases light. In another aspect, the first or the second light source is a pulsed laser thereby to produce an improved voxel to background emission. In another aspect, the first and the second light source scan across the medium, wherein the optical molecular switch molecule that excite and emit light in the medium create the three dimensional image. In another aspect, the molecule is selected from at least one of an acridine, an anthracene, an arylmethine, a cyanin, a coumarin, an oxacine, an oxadiazole, a naphthalene, a pyrene, a squaraine, a tetrapyrrole, a xanthene, a spirhodamine, or other common fluorescent, phosphorescent, long-lifetime luminescent, or chemiluminescent scaffolds, or derivatives thereof. In another aspect, the optical molecular switch molecule is attached to the medium. In another aspect, the medium is liquid, solid, a liquigel, organic, inorganic, thixotropic, a crystal, a glass, a gel, a polymer, a gas, and combinations thereof. In another aspect, the light sources are selected to match the wavelength of excitation of the optical molecular switch molecule. In another aspect, the optical molecular switch molecule is a protein. In another aspect, the optical molecular switch molecule is a green fluorescent protein, cyan fluorescent protein, yellow fluorescent protein, red fluorescent protein, gold fluorescent protein and combinations thereof. In another aspect, the optical molecular switch molecule is a saturation dye, an acceptor fluorophore, a donor fluorophore, and combinations thereof. In another aspect, the optical molecular switch molecule is capable of energy transfer selected from fluorescence resonance energy transfer (FRET), or fluorescence resonance energy transfer (FRET) with a molecular-beacon. In another aspect, at least three optical molecular switch molecules are selected to provide at least three different colors that provide for color images. In another aspect, the three dimensional image can be viewed without glasses or tricking the brain to appear three-dimensional. In another aspect, the three dimensional image is volumetric. In another aspect, the first, the second or both light sources are lasers. In one aspect, the optical molecular switch molecule is resuspended in a solvent or a base selected from at least one of dioxane, tetrahydrofuran, acetone, methanol, ethanol, isopropanol, water, diisopropyl ethylamine, pyridine, carbonate, or bicarbonate. In another aspect, each of the first light source or the second light source projects a three-dimensional images by rapid scanning of the first or second light source, and the other light source is synchronized with a changing patterned of light to form a three dimensional image in the medium. In another aspect, each of the first light source or the second light source displays a three-dimensional image by projecting light into a woven pattern into the medium. In another aspect, each of the first light source or the second light source displays a three-dimensional image by projecting light into a diagonal pattern into the medium. In another aspect, an agent that filters stray light is provided in the medium or a surface of a vessel that contains the medium. In another aspect, an angle formed between the light emitted from the first light source and the light emitted by the second light sources is at an angle other than 90 degrees. In another aspect, the first light source is a UV projector with a short pass filter, and the second light source uses a long pass filter before a camera. In another aspect, the short pass filter is a 395 nm filter, and the long pass filter is at least one of a 515, a 550, or a 590 nm filter. 
         [0011]    In yet another embodiment, the present invention includes a non-transitory computer program product, which, when executed by a processor, causes the processor to: obtain from a memory a position in a first and a second dimension an image stored in the memory; and direct a first and a second light source (e.g., a laser or a digital light processor) into a medium based on the first and the second dimensions of the image stored in the memory, wherein the medium comprises an optical molecular switch molecule, wherein the optical molecular switch molecule has a non-fluorescent state and a fluorescent state, wherein at one wavelength of optical excitation the optical molecular switch molecule has a first state and at a second state the molecule fluoresces a second wavelength of excitation, and wherein the first and the second light sources are directed into the medium to convert the optical molecular switch molecule into a fluorescent “on state” by irradiation from the first light source, and when the second light source irradiates the optical molecular switch molecule in the “on state” the optical molecular switch molecule emits light at a specific location in the medium. In one aspect, when the first and the second light source intersect the optical molecular switch molecule excites and releases light. In another aspect, the first or the second light source is a pulsed laser thereby to produce an improved voxel to background emission. In another aspect, the first and the second light source scan across the medium, wherein the optical molecular switch molecule that excite and emit light in the medium create the three dimensional image. In another aspect, the molecule is selected from at least one of an acridine, an anthracene, an arylmethine, a cyanin, a coumarin, an oxacine, an oxadiazole, a naphthalene, a pyrene, a squaraine, a tetrapyrrole, a xanthene, a spirhodamine, or other common fluorescent, phosphorescent, long-lifetime luminescent, or chemiluminescent scaffolds, or derivatives thereof. In another aspect, the optical molecular switch molecule is attached to the medium. In another aspect, the medium is liquid, solid, a liquigel, organic, inorganic, thixotropic, a crystal, a glass, a gel, a polymer, a gas, and combinations thereof. In another aspect, the light sources are selected to match the wavelength of excitation of the optical molecular switch molecule. In another aspect, the optical molecular switch molecule is a protein. In another aspect, the optical molecular switch molecule is a green fluorescent protein, cyan fluorescent protein, yellow fluorescent protein, red fluorescent protein, gold fluorescent protein and combinations thereof. In another aspect, the optical molecular switch molecule is a saturation dye, an acceptor fluorophore, a donor fluorophore, and combinations thereof. In another aspect, the optical molecular switch molecule is capable of energy transfer selected from fluorescence resonance energy transfer (FRET), or fluorescence resonance energy transfer (FRET) with a molecular-beacon. In another aspect, at least three optical molecular switch molecules are selected to provide at least three different colors that provide for color images. In another aspect, the three dimensional image can be viewed without glasses or tricking the brain to appear three-dimensional. In another aspect, the three dimensional image is volumetric. In another aspect, the first, the second or both light sources are lasers. In one aspect, the optical molecular switch molecule is resuspended in a solvent or a base selected from at least one of dioxane, tetrahydrofuran, acetone, methanol, ethanol, isopropanol, water, diisopropyl pyridine, carbonate, or bicarbonate. In another aspect, each of the first light source or the second light source projects a three-dimensional images by rapid scanning of the first or second light source, and the other light source is synchronized with a changing patterned of light to form a three dimensional image in the medium. In another aspect, each of the first light source or the second light source displays a three-dimensional image by projecting light into a woven pattern into the medium. In another aspect, each of the first light source or the second light source displays a three-dimensional image by projecting light into a diagonal pattern into the medium. In another aspect, an agent that filters stray light is provided in the medium or a surface of a vessel that contains the medium. In another aspect, an angle formed between the light emitted from the first light source and the light emitted by the second light sources is at an angle other than 90 degrees. The skilled artisan will recognize that by tilting the light source it allows image construction in two or three dimensions. In another aspect, the first light source is a UV projector with a short pass filter, and the second light source uses a long pass filter before a camera. In another aspect, the short pass filter is a 395 nm filter, and the long pass filter is at least one of a 515, a 550, or a 590 nm filter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures and in which: 
           [0013]      FIG. 1  shows a diagram of a system and method for a three-dimensional optical switch display of the present invention. 
           [0014]      FIGS. 2A and 2B  show voxel formation using a solution of a spirolactam rhodamine optical switch and purple (405 nm) and green (532 nm) laser pointers. In  FIG. 2A , a red voxel is displayed at the intersection of the two laser beams. In  FIG. 2B  the voxel can be moved by changing the point of intersection of the two beams, establishing the foundation for three-dimensional image creation. 
           [0015]      FIGS. 3A and 3B  show a pulsed method for decreasing background during voxel formation using a solution of a spirolactam rhodamine optical switch and a purple (405 nm) and green (532 nm) laser pointer. In  FIG. 3A  a red voxel is displayed at the intersection of the two laser beams after a pulse with the 405 nm laser pointer. In  FIG. 3B  the voxel can be moved by changing the point of intersection of the two beams, establishing the foundation for three-dimensional image creation. 
           [0016]      FIG. 4  shows an example of a set-up of the present invention. 
           [0017]      FIG. 5  shows a dual Digital Light Processor (DLP) projection system is used to display three-dimensional images ( FIG. 5 ). 
           [0018]      FIG. 6  shows a custom-DLP projector  3  (Wintech) equipped with a 385 nm LED and a Miroir HD 720p picoprojector  2  equipped with RGB LEDs irradiates the small molecule optical switch solution ( 1 ) plus chemical additives to fine-tune the switching properties. 
           [0019]      FIG. 7A  shows the image projected from the RGB projector.  FIG. 7B  shows the image projected from the UV projector.  FIG. 7C  shows the three-dimensional image, a row of squares, where the green and UV patterned light intersects.  FIG. 7D  is the same image in  FIG. 7C , but viewed at a different angle. 
           [0020]      FIG. 8A  shows the image projected from the RGB projector.  FIG. 8B  shows the image projected from the UV projector.  FIG. 8C  shows the three-dimensional image, a 5×4 grid of bars, where the green and UV patterned light intersects.  FIG. 8D  is the same image in  FIG. 8C , but viewed at a different angle. 
           [0021]      FIG. 9A  shows the image projected from the RGB projector.  FIG. 9B  shows the image projected from the UV projector.  FIG. 9C  shows the three-dimensional image, the SMU Mustang logo, where the green and UV patterned light intersects. 
           [0022]      FIG. 10A  shows the image projected from the RGB projector.  FIG. 10B  shows the image projected from the UV projector.  FIG. 10C  shows the three-dimensional image, the SMU Mustang logo, where the green and UV patterned light intersects. 
           [0023]      FIG. 11A  shows the image projected from the RGB projector.  FIG. 11B  shows the image projected from the UV projector.  FIG. 11C  shows the three-dimensional image, a heart in the middle of the image chamber, where the green and UV patterned light intersects. 
           [0024]      FIG. 12A  shows the image projected from the RGB projector.  FIG. 12B  shows the image projected from the UV projector.  FIG. 12C  shows the three-dimensional image, a pyramid, where the green and UV patterned light intersects. 
           [0025]      FIG. 13A  shows the image projected from the RGB projector.  FIG. 13B  shows the image projected from the UV projector.  FIG. 13C  shows the three-dimensional image, a rectangular prism, where the green and UV patterned light intersects. 
           [0026]      FIG. 14  shows a dual Digital Light Processor (DLP) projection system is used to display arbitrary three-dimensional images by rapid scanning of UV planes of light synchronized with a changing patterned light from the RGB projector ( FIG. 14 ). 
           [0027]      FIG. 15A  shows the image projected from the RGB projector, a four-fold gridded pattern of green light.  FIG. 15B  shows the image projected from the UV projector, an interwoven pattern of two images.  FIG. 15C  shows the three-dimensional image, a heart in front of a triangle, where the green and UV patterned light intersects. 
           [0028]      FIG. 16A  shows the image projected from the RGB projector, a six-fold gridded pattern of green light.  FIG. 16B  shows the image projected from the UV projector, an interwoven pattern of two images.  FIG. 16C  shows the three-dimensional image, a heart in front of a triangle, where the green and UV patterned light intersects. 
           [0029]      FIG. 17A  shows the image projected from the RGB projector, a series of diagonal lines.  FIG. 17B  shows the image projected from the UV projector, three distorted triangle that when projected onto the diagonal green lines will form triangular cross-sections.  FIG. 17C  shows the three-dimensional image, three triangles stacked atop each other. 
           [0030]      FIGS. 18 and 19  show images projected using a dual Digital Light Processor (DLP) projection system to display three-dimensional images using a 395 nm short pass filter in front of the UV projector and a 515 nm, 550 nm, or 590 nm long pass filter in front of the camera ( FIG. 18, 19 ). 
           [0031]      FIGS. 20A and 20B  show images with optimization of imaging distances, which enables high-resolution images of the subjects. 
           [0032]      FIGS. 21A, 21B and 21C  shows a progression of images in an animation at 30 fps at the listed times, the college mascot at the bottom right can be seen running. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0033]    While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention and do not delimit the scope of the invention. 
         [0034]    To facilitate the understanding of this invention, a number of terms are defined below. Terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the present invention. Terms such as “a”, “an” and “the” are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration. The terminology herein is used to describe specific embodiments of the invention, but their usage does not delimit the invention, except as outlined in the claims. 
         [0035]    Traditional three-dimensional (3D) stereoscopic displays (i.e., including 3D glasses or holography) do not produce ‘true’ 3D images, relying instead on ‘tricking’ the brain into a 3D appearance. Truly 3D images, however, can be generated by a volumetric display, a device that forms a visual representation of an object in three physical dimensions, as opposed to a planar image on traditional screens that simulate depth through a number of different visual effects. Unique properties of volumetric displays include 360-degree viewing, agreement of converge and accommodation cues and their inherent 3D format, also enabling innovative user-interface techniques. However, current volumetric displays have several major disadvantages including complexity and cost. For example, volumetric imaging systems generally require: laser scanner hardware, relatively high power lasers (or bulky light source arrays) for excitation processes and/or advanced materials (e.g. plasma emission) and a variety of moving parts, lenses, mirrors and the like. These requirements contribute to the cost of such systems, making its wide commercial implementation impractical. Known volumetric display technologies also have several drawbacks including: a failure to represent occlusion and opacity, and 3D-scene distortion when viewed from non-predicted locations. Additional drawbacks include a large amount of bandwidth or throughput required to feed images into a high-resolution volumetric display. Thus, a need remains for improved and/or low-cost volumetric displays. 
         [0036]    The present invention addresses these key problems with current volumetric displays, and may be used in a wide range of applications in different sectors, including but not limited to, medical, aerospace and defense, automotive, and industrial. Further, higher availability and lower-cost 3D displays will find wider applications in biomedical imaging, scientific and industrial image rendering, entertainment and communication. 
         [0037]    The disclosed invention includes a system and method for a volumetric three-dimensional optical switch display (OSD) device. A low cost three-dimensional display has enormous commercial potential not only in the entertainment industry, but also for biomedical imaging, scientific and industrial image rendering, and communication applications. Traditional three-dimensional displays, including stereoscopic (i.e. 3D glasses) or holography are not true three-dimensional images and rely on tricking the eyes and the brain to “appear” three-dimensional. 
         [0038]    The system and method of the present invention generates truly three-dimensional volumetric images. While volumetric imaging systems have been reported in prior art, they generally require moving parts, high power lasers for upconversion processes, bulky light source arrays, or advanced metamaterials. These limitations all contribute to the expense of such systems as well as making large-scale implementation impractical. The present invention enables the generation of voxels (three dimensional pixels) using small organic molecules called “optical switches” and two lasers of appropriate wavelengths. 
         [0039]    One example of the present invention relies on a newly conceived optical switch display technology. An optical switch is an organic molecule that can change its shape and properties in response to irradiation with an appropriately tuned light source. In our invention, we utilize optical switches that transform from a non-fluorescent “off state” into a fluorescent “on state” upon irradiation with one wavelength of light. In the “on state”, the optical switch can be made to fluoresce by irradiation with a second light source of the appropriate wavelength. If the optical switch is properly designed, it will quickly relax back to the “off state” and no longer fluoresce. When dispersed in solution or in a transparent polymeric matrix (i.e. a three-dimensional “screen”), a voxel of light appears only where the two light sources cross. 
         [0040]    In one embodiment ( FIG. 1 ), a spirolactam rhodamine optical switch can be switched to the fluorescent “on state” using a low power 5 mW 405 nm laser (i.e. a purple laser pointer). Without 405 nm irradiation, the spirolactam rhodamine optical switch rapidly relaxes back to the nonfluorescent “off state”. While receiving continuous 405 nm irradiation to keep the optical switch in the “on state”, it will fluoresce with an emission maximum of 565 nm (red) upon irradiation with a low power 5 mW 532 nm laser (i.e. a green laser pointer). The net result is that a solution of the spirolactam rhodamine optical switch will display a three-dimensional voxel of light only where the two lasers intersect. In one embodiment ( FIGS. 2A and 2B ), the 405 nm and 532 nm lasers are simultaneously aimed into a solution of the spirolactam rhodamine optical switch, and a voxel of light is seen at the intersection of the beams ( FIG. 2A ). A low background trace of the laser beams can be seen where they do not intersect, an issue that will be fixed by optimization of the optical switch chemistry and/or use of appropriate band-pass filters. The lasers are moved in  FIG. 2B , demonstrating the ability to manipulate the three-dimensional voxel. This design establishes the foundation for laser scanning to be used to generate full three-dimensional images. 
         [0041]    In a second embodiment, increased voxel to background emission is accomplished using a pulsed laser method. Using a spirolactam rhodamine optical switch where the relaxation from the fluorescent “on state” to the non-fluorescent “off state” is on the time scale of seconds enables a system where the 405 nm laser can first be pulsed to induce the spirolactam rhodamine optical switch into the fluorescent “on state” in the path of the beam. The 405 nm laser can then be removed and the spirolactam rhodamine optical switch will remain in the fluorescent “on for several seconds. Irradiation with the 532 nm laser induces fluorescence only where it crosses along the path of the previous 405 nm irradiation ( FIG. 3A ). The pulse can be repeated at a different location to produce a voxel at a different location ( FIG. 3B ). The precise kinetics and optics can be tuned to provide a system amenable to laser scanning and low cost three-dimensional displays. 
         [0042]      FIG. 4  shows an example of a set-up of the present invention. The volumetric display system  10 , is depicted showing the positioning of a first light source  12 , and a second light source  14 , directed at a vial  16 , which contains the medium  18 . As described hereinabove, the results of using the invention, as shown in  FIGS. 2A, 2B, 3A and 3B  are shown in medium  18 . 
         [0043]    In a third embodiment, a dual Digital Light Processor (DLP) projection system is used to display three-dimensional images ( FIG. 5 ). As shown in  FIG. 6 , a custom-DLP projector  3  (Wintech) equipped with a 385 nm LED and a Miroir HD 720p picoprojector  2  equipped with RGB LEDs irradiates the small molecule optical switch solution  1  plus chemical additives to fine-tune the switching properties.  FIG. 6  also shows that the Miroir HD 720p picoprojector  2  includes an HDMI connector  4 , and power supply  5 . The custom-DLP projector  3  includes a USB connector  6 , an HDMI connector  7 , and a power supply  8 . At the intersection of the patterned light red fluorescence will be observed, generating a volumetric display in three-dimensional space. 
         [0044]    Three example of images generated using the set-up of  FIG. 6  are shown in  FIGS. 7-9  using 5 mM N-Phenyl Spirhodamine in dichloromethane containing 0.0001% triethylamine. Other solvents and bases can be used including, but not limited to dioxane, tetrahydrofuran, acetone, methanol, ethanol, isopropanol, water, diisopropyl ethylamine, pyridine, carbonate, bicarbonate, etc.  FIG. 7A  shows the image projected from the RGB projector.  FIG. 7B  shows the image projected from the UV projector.  FIG. 7C  shows the three-dimensional image, a row of squares, where the green and UV patterned light intersects.  FIG. 7D  is the same image in  FIG. 6C , but viewed at a different angle. In a second example,  FIG. 8A  shows the image projected from the RGB projector.  FIG. 8B  shows the image projected from the UV projector.  FIG. 8C  shows the three-dimensional image, a 5×4 grid of bars, where the green and UV patterned light intersects.  FIG. 8C  is the same image in  FIG. 8C , but viewed at a different angle. In a third example,  FIG. 9A  shows the image projected from the RGB projector.  FIG. 9B  shows the image projected from the UV projector. Note that the UV projector outputs 385 nm light, even though the input is a red image.  FIG. 9C  shows the three-dimensional image, the SMU Mustang logo, where the green and UV patterned light intersects. 
         [0045]    In a fourth embodiment, a dual Digital Light Processor (DLP) projection system is used to display three-dimensional images in combination with an optical filter to remove unwanted blue light, increasing resolution and contrast. A custom-DLP projector (Wintech) equipped with a 385 nm LED and a Miroir HD 720p picoprojector equipped with RGB LEDs will irradiate the small molecule optical switch solution plus chemical additives to fine-tune the switching properties. At the intersection of the patterned light red fluorescence will be observed, generating a volumetric display in three-dimensional space. Four example images are shown in  FIGS. 10-13 .  FIG. 10A  shows the image projected from the RGB projector.  FIG. 10B  shows the image projected from the UV projector.  FIG. 10C  shows the three-dimensional image, the SMU Mustang logo, where the green and UV patterned light intersects. In a second example,  FIG. 11A  shows the image projected from the RGB projector.  FIG. 11B  shows the image projected from the UV projector.  FIG. 11C  shows the three-dimensional image, a heart in the middle of the image chamber, where the green and UV patterned light intersects. In a third example,  FIG. 12A  shows the image projected from the RGB projector.  FIG. 12B  shows the image projected from the UV projector.  FIG. 12C  shows the three-dimensional image, a pyramid, where the green and UV patterned light intersects. In a fourth example,  FIG. 13A  shows the image projected from the RGB projector.  FIG. 13B  shows the image projected from the UV projector.  FIG. 13C  shows the three-dimensional image, a rectangular prism, where the green and UV patterned light intersects. 
         [0046]    In a fifth embodiment, a dual Digital Light Processor (DLP) projection system is used to display arbitrary three-dimensional images by rapid scanning of UV planes of light synchronized with a changing patterned light from the RGB projector ( FIG. 14 ). Supplementary Movie  1  shows the movie projected from the RGB projector. Supplementary Movie  2  shows the movie projected from the UV projector. Supplementary Movie  3  shows the three dimensional image, cross-sections of a sphere. Rapid scanning and proper phasing will provide a method for arbitrary three-dimensional image generation. 
         [0047]    In a sixth embodiment, a dual Digital Light Processor (DLP) projection system is used to display arbitrary three-dimensional images by projecting light into a woven pattern with UV and green light intersecting at points defined along the height of the imaging chamber. Three examples are shown in  FIGS. 15-17 .  FIG. 15A  shows the image projected from the RGB projector, a four-fold gridded pattern of green light.  FIG. 15B  shows the image projected from the UV projector, an interwoven pattern of two images.  FIG. 15C  shows the three-dimensional image, a heart in front of a triangle, where the green and UV patterned light intersects. Note that the heart sections intersect with one gridded plane of green light and the triangle sections intersect with a different gridded plan of green light. In a second example,  FIG. 16A  shows the image projected from the RGB projector, a six-fold gridded pattern of green light.  FIG. 16B  shows the image projected from the UV projector, an interwoven pattern of two images.  FIG. 16C  shows the three-dimensional image, a heart in front of a triangle, where the green and UV patterned light intersects. Note that the heart sections intersect with one gridded plane of green light and the triangle sections intersect with a different gridded plan of green light. In a third example,  FIG. 17A  shows the image projected from the RGB projector, a series of diagonal lines.  FIG. 17B  shows the image projected from the UV projector, three distorted triangle that when projected onto the diagonal green lines will form triangular cross-sections.  FIG. 17C  shows the three-dimensional image, three triangles stacked atop each other. 
         [0048]      FIGS. 18-21  show yet another aspect of the present invention. In  FIGS. 18 and 19 , a dual Digital Light Processor (DLP) projection system is used to display three-dimensional images using a 395 nm short pass filter in front of the UV projector and a 515 nm, 550 nm, or 590 nm long pass filter in front of the camera.  FIGS. 20A and 20B  show high-resolution images of the inventors in which the imaging distances were optimized.  FIGS. 20A to 20C  shows a series of animations at 30 fps, in which a college mascot can be seen running in three dimensions. 
         [0049]    It is contemplated that any embodiment discussed in this specification can be implemented with respect to any method, kit, reagent, or composition of the invention, and vice versa. Furthermore, compositions of the invention can be used to achieve methods of the invention. 
         [0050]    It will be understood that particular embodiments described herein are shown by way of illustration and not as limitations of the invention. The principal features of this invention can be employed in various embodiments without departing from the scope of the invention. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, numerous equivalents to the specific procedures described herein. Such equivalents are considered to be within the scope of this invention and are covered by the claims. 
         [0051]    All publications and patent applications mentioned in the specification are indicative of the level of skill of those skilled in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. 
         [0052]    The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.” The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or the alternatives are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.” Throughout this application, the term “about” is used to indicate that a value includes the inherent variation of error for the device, the method being employed to determine the value, or the variation that exists among the study subjects. 
         [0053]    As used in this specification and claim(s), the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps. In embodiments of any of the compositions and methods provided herein, “comprising” may be replaced with “consisting essentially of” or “consisting of”. As used herein, the phrase “consisting essentially of” requires the specified integer(s) or steps as well as those that do not materially affect the character or function of the claimed invention. As used herein, the term “consisting” is used to indicate the presence of the recited integer (e.g., a feature, an element, a characteristic, a property, a method/process step or a limitation) or group of integers (e.g., feature(s), element(s), characteristic(s), propertie(s), method/process steps or limitation(s)) only. 
         [0054]    The term “or combinations thereof” as used herein refers to all permutations and combinations of the listed items preceding the term. For example, “A, B, C, or combinations thereof” is intended to include at least one of: A, B, C, AB, AC, BC, or ABC, and if order is important in a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB. Continuing with this example, expressly included are combinations that contain repeats of one or more item or term, such as BB, AAA, AB, BBC, AAABCCCC, CBBAAA, CABABB, and so forth. The skilled artisan will understand that typically there is no limit on the number of items or terms in any combination, unless otherwise apparent from the context. 
         [0055]    As used herein, words of approximation such as, without limitation, “about”, “substantial” or “substantially” refers to a condition that when so modified is understood to not necessarily be absolute or perfect but would be considered close enough to those of ordinary skill in the art to warrant designating the condition as being present. The extent to which the description may vary will depend on how great a change can be instituted and still have one of ordinary skilled in the art recognize the modified feature as still having the required characteristics and capabilities of the unmodified feature. In general, but subject to the preceding discussion, a numerical value herein that is modified by a word of approximation such as “about” may vary from the stated value by at least ±1, 2, 3, 4, 5, 6, 7, 10, 12 or 15%. 
         [0056]    All of the compositions and/or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and/or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.