Abstract: A holographic sight which includes a base having at least one connector for mounting the base on a small arm, and a hologram of a reticle pattern, a compact laser light source for illuminating the hologram, and a power source for the laser diode, each mounted on the base. The sight also includes an achromatizer supported in the path of the light beam for reducing shifts in the position of the reticle pattern due to variations in the wavelength of the light beam emitted from the laser diode. The sight may further include means for circularizing the generally elliptical beam emitted by the laser diode to provide a uniform illumination pattern for the hologram. A brightness adjuster and position adjuster, for varying the brightness and relative position of the reticle, respectively, may also be provided.

Abstract: In a nanometer order dot pattern producing method and drawing apparatus by electron holography, a nanometer order dot pattern is readily produced with a high accuracy, using a pair of biprisms or multi-biprisms integrated as a unit so as to mutually cross. Each multi-biprism includes a plurality of biprisms arranged in parallel. Electric potentials of the integrated biprisms or multi-biprisms are independently controlled.

Abstract: The optically variable image in optically variable imaging devices, such as holograms, kinegrams, pixelgrams and interference gratings, is enhanced by coating the image relief or interference pattern with a thin film of a synthesized high oxygen content oxide of bismuth wherein the atomic ratio of oxygen to bismuth is 1.7 or greater, i.e., BiO.sub.x (x=>1.7).A process for applying a thin film of the synthesized high oxygen content BiO.sub.x to the relief or interference pattern comprises reactive deposition of bismuth in an oxygen partial pressure atmosphere wherein the oxygen partial pressure and the dynamic deposition rate are correlated to achieve the desired degree of oxidation of the bismuth.The process also lends itself to dynamic deposition of other image enhancing materials, as well as protective coatings for the image enhancing materials.

Abstract: A holographic product with sealed edges which will resist delamination before and after attachment to a substrate when exposed to moisture or abrasion resulting from ordinary usage. The holographic product comprises a transparent abrasion resistant moisture impervious plastic top layer, an adhesive bottom layer, an intermediate reflective surface or layer and a seal along the entire perimeter. The seal is preferably produced by a hot cutting tool.

Abstract: To servocontrol the direction and the position of a collimation mirror of a head-up visor, holographic elements are used. These holographic elements deflect a part of the light reflected by the mirror towards sensors located outside the field of view.

Abstract: A process for producing an optical data storage disc (e.g., a compact disc) carrying a digital recording and also carries a holographic image is disclosed. The holographic recording occupies an area (14) separate from the area (12) occupied by the digital recording, for example, the holographic recording may be positioned in an annular area encircling the central area occupied by the digital recording.

Abstract: A new type of holographic recording in photorefractive crystals is disclosed, termed orthogonal data storage, in which counterpropagating, reflection mode holograms are wavelength multiplexed to form gratings lying along a common axis. It is shown that this configuration provides substantial improvements in data storage capacity in comparison to prior art systems and that higher coupling coefficients are achieved. In consequence, not only storage of data but a wide range of other devices including wavelength selective filters, lenses and optical correlation systems are disclosed. Further, methods of writing and processing metastable images are disclosed which substantially improve the strength of the gratings that are permanently developed in the medium. These methods include advantageous use of electrical potentials and photovoltaic properties, together with different interrelationships during processing.

Abstract: A neural network has inputs formed by square array of optical modulators M.sub.ij and outputs by optical detectors D.sub.ij coupled to threshold comparators. A holographic plate includes a spatial modulator whose elements are controlled by a controller to form an array of optical beams from a coherent optical source. Each optical beam optically interconnects a modulator M.sub.ij with a respective detector D.sub.ij. The weight values of the neural network are provided by the intensities of the optical beams. This obviates the need for an optical weighting mask between an array of light emitting diodes and a detector array allowing a higher density of lower power consumption components and reprogrammability of the network.

Abstract: Holographic flake pigments, processes for making the pigments, decorative coatings comprising the pigments, and articles comprising the decorative coatings are disclosed. The pigment comprises particles that (1) comprise an organic polymer and further comprise one or more volume phase holograms; and (2) have a thickness of about 1 micrometer to about 100 micrometers, an average diameter of about 10 micrometers to about 300 micrometers, and a thickness to diameter ratio of about 1:2 to about 1:60.

Abstract: A photopolymerizable composition includes a water-insoluble olefinic compound that is polymerizable with free-radical initiators, an oil-soluble phenothiazine dye that is soluble in water-immiscible organic solvents, and a reducing agent operable to react with the dye to form reactive free radicals only when the dye is in an excited state induced by exposure to light. The reducing agent and the dye are reacted together under the influence of light, and particularly red light. The resulting reactive free radicals cause the olefinic compound to polymerize to a polymer that is substantially unaffected by the presence of moisture.

Abstract: There is described a semiconductor microcrystallite doped glass that exhibits SHG, and a method of preparing, or encoding, a semiconductor microcrystallite doped glass by the simultaneous injection of fundamental and second harmonic fields, such as 1.06 .mu.m and 532 nm. More specifically, the disclosure pertains to a structure that exhibits SHG, the structure being comprised of, by example, borosilicate glass that contains CdS.sub.x Se.sub.1-x microcrystallites. Also disclosed are embodiments of devices having an optical waveguide structure formed within a glass substrate that contains semiconductor microcrystallites. The optical waveguide structure guides and contains injected radiation and also converts a portion thereof to the second harmonic. Also disclosed are optoelectronic devices that include frequency doublers, self-doubling lasant material, bichromatic optical switches, and a volume holographic medium, all of which include a glass host having semiconductor microcrystallites embedded within.

Abstract: An apparatus detects a target reactant that binds to an immobilized reactant. The apparatus generates a holographic image at a predetermined location when the reactants are present and bound to one another. The immobilized reactant is bound to a support surface at selected locations. The locations are chosen such that a holographic plate is generated when the target reactant binds to the immobilized reactant. An associated method may be used to detect antibody-antigen reactions, the binding of two strands of nucleic acid, the binding of an enzyme to one of its substrates, and so on.

Abstract: A holographic center high mounted stop light (CHMSL) employing a linear lamp source comprising a long and narrow cylindrical gas discharge bulb, a non-imaging light concentrator cavity, a plastic light guide and a hologram. The CHMSL is characterized by previously unattainable compactness, weight savings, rear occupant headroom, driver rearward visibility, and electrical efficiency.

Abstract: An intermediate transfer medium comprises a heat-resistant base sheet and provided thereon a release layer and an image-receiving adhesive layer on which an image pattern is formed by a sublimation transfer means in accordance with image data, said image-receiving adhesive layer, on which said image pattern has been formed, being transferred to a transfer substrate together with said release layer to produce an image-recorded article, wherein said image-receiving adhesive layer is comprised of a thermoplastic resin having a glass transition point of 50.degree. C. or above and a filler added to the thermoplastic resin and selected from the group consisting of an inorganic filler having a melting point of 200.degree. C. or above and an organic filler having a softening point or decomposition point of 200.degree. C. or above.

Abstract: An apparatus is proposed for making absolute, two-dimensional measurements of the position of an object (10) with reference to a measuring arrangement (11), with the surface of the object (10) being configured as a hologram. The information contained in the hologram is red out by means of a measuring wave (13) that is directed onto the hologram (18), is diffracted there and interferes with a reference wave (14). The interfered-with waves (13, 14) are picked up by an optical sensor arrangement (20) including at least two sensors (21, 22). In a signal processing arrangement (23), the absolute position is determined either from the radiation intensities picked up by the sensors (21, 22) or from the phase relationship between the signals emitted by the sensors (21, 22), in each case by a comparison with a value stored in a memory.

Abstract: An improved method for storing permanent holographic gratings in photorefractive materials for use in narrow band filters such as the H.sub.60 filter, as well as the filters themselves. The invention also provides an improved method of controlling the electric field and the nature of the photorefraction to minimize wavelength shifts and band broadening at a minimal reduction of diffraction efficiency.

Abstract: Reflection holograms to be viewed through the front side of a transparent and preferably flexible substrate, and which are insensitive to moisture in liquid and in vapor form, are produced by attaching a layer of holographic recording material to the back side of a transparent substrate, attaching a layer of moisture barrier resin to the back side of the recording material in sufficient thickness to render the hologram insensitive to moisture, and attaching a layer of opaque material to the back side of the moisture barrier layer. Further protection against moisture may be achieved by attaching a solvent deposited layer of transparent moisture barrier resin to the front side of the substrate and/or attaching a layer of moisture barrier sheet to the back side of the opaque layer.

Abstract: A hologram system comprises two volume holograms on two separate substrates which are cemented together with an optical cement. The two volume holograms are manufactured with identical Bragg planes. The two volume holograms are oriented with respect to one another such that the Bragg planes are optically aligned. The result is that the two volume holograms operate as a single thicker volume hologram wherein the Bragg angle sensitivity is greatly increased.

Abstract: A hologram includes an optically transparent base plate having first and second opposite surfaces. A hologram element is provided on the first surface of the base plate, and has a predetermined holographic pattern. An optically transparent member has first and second opposite surfaces. The first surface of the member faces the hologram element. An arrangement serves to prevent light, which successively passes through the transparent base plate, the hologram element, and the member and is then reflected at a boundary between the second surface of the member and an atmosphere, from travelling back to the hologram element.

Abstract: An image of an object embedded in a diffusing medium is formed by propagating a coherent or equivalent light pulse through the diffusing medium and applying a reference pulse so as to gate precisely the first emerging light transmitted through the diffusing medium. An ultra-short pulse, having a duration on the order of 150 fs, insures that only the first emerging light is used to form a hologram. Instability in the diffusing medium, which may be inherent therein, as is the case with living tissue, or artificially induced therein, such as by vibrating the specimen, ensures that a subsequent hologram has a different background noise and speckle pattern. Integration of such holograms causes the background noise to average out, but time-invariant features, such as the object being imaged, become increasingly more visible as more holograms are integrated.

Abstract: A light box includes a lower casing and an upper casing pivotally connected to the lower casing. A lighting element is pivotally mounted to the inner side of the lower casing. A plurality of pairs of spaced ridges are provided on both longitudinal sides of the inner periphery of the lower casing. A plate is pivotally received in the inner side of the upper casing at an upper side thereof. The lower side of the plate is selectively supported by one of the pairs of the ridges. A hologram is provided on one side of the plate which faces the lighting element. When the upper casing is opened to a pre-determined extent, the lighting element is switched on. Under adjustment of the inclination of the hologram plate and the lighting element, a viewer may appreciate various images contained in the hologram.

Abstract: A holographic display and method for displaying hologram are disclosed. The method and apparatus provides a compact display arrangement in which the light source for illuminating the display is integral with the display, or in other words, an external light source is not necessary. The hologram utilized in the display is formed as a rainbow hologram, with a converging reference beam utilized in forming the diffraction grating upon the holographic plate. The display includes a pair of spaced transparent glass sheets, with the light source disposed between the glass sheets. The holographic plate formed with the converging reference beam is then mounted upon one of the glass sheets, with the light source illuminating the holographic plate with diverging illumination light. A mirror is associated with each of the transparent glass sheets at a location adjacent to the light source, with the reflective surfaces of the mirrors facing each other.

Abstract: A high finesse holographic Fabry-Perot etalon and method of making a high finesse holographic Fabry-Perot etalon is disclosed. Particularly, a holographic Fabry-Perot etalon which achieves high finesse despite non-flat interfaces between the etalon media is presented. In a preferred method of fabricating a high finesse Fabry-Perot etalon, single step recording of both holograms simultaneously, with the spacer and substrates in place, is employed which preserves full phase synchronization between the holograms. In spite of imperfections or irregularities of the interface surfaces of the substrates or spacers, the holographic fringes in the holograms remain flat even for slightly different refractive indices between the various media. The position and flatness of the fringes remains similar to perfect Fabry-Perot etalon structure.

Abstract: A method and apparatus for highly efficient use of higher-order diffraction beam in holography. The thermoplastic hologram (10) is recorded at a recording angle (.theta..sub.R) between two coherent beams (12, 14) equal to a first-order diffraction angle (.theta..sub.1) corresponding to the angle (.theta..sub.2) of the desired higher-order beam (18) set to the angular peak (22) of diffraction efficiency (20) of the material of the hologram. On read-out, the desired higher-order beam is read. By use of the invention, the intensity of a higher-order beam can be tuned and made nearly equal to that of the first-order beam. Thereby, useful non-linear holographic systems, such as an associative memory (FIG. 4), can be practically implemented.

Abstract: A method and an apparatus for making a hologram wherein interference patterns to be recorded on a hologram plate are prevented from travelling, thereby enabling a high quality hologram to be made.

Abstract: A hologram exposure apparatus for and method of obtaining a hologram using a photoresist for an in-line type interferometer wherein a photoresist substrate is detachably mounted on a substrate rotating device. A concentric pattern of a hologram from a source of light is projected onto the photoresist on the substrate mounted on the substrate rotating device while rotating the substrate and moving a projecting device in a direction at right angles with the rotary shaft of the photoresist substrate.

Abstract: A diamondlike carbon thin film protected hologram comprises an organic film deposited on a substrate and recorded to form a hologram, and a diamondlike carbon thin film deposited on the hologram, or first and second substrates having a diamondlike carbon thin film deposited thereon and an organic film having a holographic pattern recorded therein and sandwiched between the diamondlike carbon thin films of the first and second substrates. A method of fabricating a diamondlike carbon thin film protected hologram comprises forming a layer of dichromated gelatin on a substrate, recording the dichromated gelatin to form a hologram, and depositing on the hologram a diamondlike carbon thin film at room temperature, or depositing a diamondlike carbon thin film on first and second substrates, forming a layer of dichromated gelatin on the thin film of one of the substrates, recording the layer to form a hologram, and adhering the thin film of the second substrate to the hologram.

Abstract: A reflection type hologram scale, in which a hologram dry plate is bonded to a protecting base member in which a hologram grating formed on a scale base member forming the hologram dry plate and a reflecting film formed on a base member forming the protecting base member are opposed to each other. Therefore, the hologram grating and the reflecting film are both protected by the scale base member and the base member so that the hologram grating and the reflecting film are prevented from being exposed to the air, thereby preventing the hologram grating and the reflecting film from being smudged by fingermarks, dust and also from being scratched.

Abstract: A holographic recording of the interference between an object laser beam and a reference laser beam is used to combine the amplitudes of multiple input laser beams which are conjugates of the reference beam, into a single output laser beam which is a conjugate of the object beam. An optical device in the form of a trapezoidal prism has an entrance top face with a diffusion surface, and an exit base face with a holographic recording made on a light sensitive recording medium of an interference pattern of an object beam incident on the diffusion surface and scattered over the recording medium, in interference with a reference beam simultaneously incident to a side of the prism onto the same medium.

Abstract: A volume phase type hologram film has a diffraction grating recorded in a film composed mainly of poly(N-vinylcarbazole). The poly(N-vinylcarbazole) as the main component has a weight-average molecular weight of not less than 1,000,000 and a molecular weight distribution of not more than 3. In the poly(N-vinylcarbazole), the content of a fraction of poly(N-vinylcarbazole) having a weight-average molecular weight of not more than 200,000 does not exceed 1% by weight.

Abstract: A holographic diffraction media is disposed on a physical object in a highly visible position so as to enhance the human visibility of the object, and therefore the safety of humans using or associated with the object. The media may be a piece of thin plastic (polyester) film with an adhesive backing, with a release paper that is removed when it is desired to attach the film to the object. The object may be a road marker, road sign, a paved road itself (i. e. the holographic media may be a lane divider or a side strip for the road), a spoked wheel, a tire with a hubcap or wheel cover, a propeller, a safety vest, or a jogging shoe (affixed to the upper heel exterior of the shoe). The holographic diffraction media is inexpensive, light weight, and is more visible in environments with low and/or diffuse light than are reflectors.

Abstract: The invention relates to a method for the photographic recording and the visual restitution of a tridimensional scene by means of a coherent light source (1). According to the invention, in view of the photographic recording, a coherent light beam is projected onto said scene such that it illuminates only a small portion of the surface of the scene (3) and a photosensitive recording plate (4) is disposed in such a way that it receives diffuse light coming from said scene; in view of the visual restitution, a first face of said plate is illuminated by a coherent light beam while the second face of said plate is observed.

Abstract: A volume phase type hologram has a diffraction lattice recorded in a poly(N-vinyl carbazole) polymer layer where the diffraction lattice is recorded throughout the thickness direction of the polymer layer. A method for preparing the volume phase type hologram has the steps of exposing a photosensitive polymer layer provided on a substrate to an interference pattern; subjecting the polymer layer having been exposed to a first development treatment with a first organic solvent; and peeling the polymer layer off the substrate and subjecting the polymer to a second development treatment with a second organic solvent preferentially from the face that had been in contact with the substrate.

Abstract: A ceiling fan includes a plurality of fan blades radially secured to a motor shaft of a driving motor of the fan, each fan blade fixed with a holographic recording plate thereon pre-recorded with holograms of many sets of interference patterns of colorful decorative features within the recording plate, whereby upon a rotation of the fan blades as driven by the driving motor as being illuminated by a plurality of lamps, the patterns of color features recorded in each holographic recording plate will be observed with diversified color changes of the decorative features and superimposed decorative feaures with respect to a rotating angle as rotated by each fan blade, thereby enriching an optical decorative effect with simpler production, easier operation and minor maintenance problems of the fan.

Abstract: A decorative promotional display signage and its method of manufacture includes the steps for combining the constituent elements of the signage, and the resultant combination of these elements. The signage includes a clear transparent substrate with an informational image created on the posterior surface of the substrate by selectively depositing transparent colored inks on this surface. Clear ink may also be deposited on selected portions of the posterior surface of the substrate to emphasize the informational image. A sheet of holographic film, to present a variable color cast to the image, is adhered to the substrate with the layers of ink positioned between the substrate and the holographic film.

Abstract: A hologram efficiency adjusting process that includes scanning the brightness effect of a hologram, which is either the hologram to be adjusted or a hologram representative of the hologram to be adjusted, to provide brightness vs. position information. The brightness information is utilized to produce a variable duty cycle half-tone mask that contains a pattern defining the areas of the hologram which are to be removed, with the pattern being unresolvable by the viewer of the hologram from which holograms have been removed pursuant to the mask pattern. The hologram to be adjusted is then photoresist coated and etched in accordance with the mask. Alternatively, the brightness information can be utilized to directly expose, for example by a laser scanner, photoresist disposed on the hologram to be adjusted.

Abstract: The method involves directing first and second separate illuminating beams towards a photosensitive film from separate fixed apparent beam source positions respectively in such a manner that the beams are caused to overlap at the point of incidence at the photosensitive film. Stationary interference fringes are generated and the beams are caused to scan in a raster type pattern over the photosensitive film in such a manner whereby overlapping of the beams is maintained throughout the exposure of the film. The apparatus in one embodiment involves the generation of a third illuminating beam which is used to control means to control an associated scanner to effect synchronised movement of the second beam with the first beam. A further embodiment involves memorising the scanning movement of beam in a memory and using the memorised scanning pattern to control the scanner to maintain beam overlap.

Abstract: A method and apparatus for three dimensional imaging of the atomic environment of disordered adsorbate atoms are disclosed. The method includes detecting and measuring the intensity of a diffuse low energy electron diffraction pattern formed by directing a beam of low energy electrons against the surface of a crystal. Data corresponding to reconstructed amplitudes of a wave form is generated by operating on the intensity data. The data corresponding to the reconstructed amplitudes is capable of being displayed as a three dimensional image of an adsorbate atom. The apparatus includes a source of a beam of low energy electrons and a detector for detecting the intensity distribution of a DLEED pattern formed at the detector when the beam of low energy electrons is directed onto the surface of a crystal.

Abstract: An apparatus for displaying a three-dimensional image of a plurality of tomographic images by storing pictorial information of a tomographic image in an image convering element, forming interference fringes between a reading light beam which is transmitted through the image converting element and is modulated in accordance with the pictorial information stored therein and a reference light beam, and recording the interference fringes on a photographic plate. A three-dimensional image is reproduced by projecting the reference light beam onto the thus developed photographic plate. The image converting element is formed by a Pockels readout optical modulator. An intensity and position of a coherent light beam is modulated in accordance with the pictorial information of the tomographic image, and the thus modulated coherent reading light beam is made incident upon the Pockels readout optical modulator.

Abstract: A hologram is used to project an image of a pattern similar to a placido upon the cornea of a subject. By viewing the reflection of the pattern in the subject's cornea, one may measure the curvature of the cornea. The use of the hologram in the keratometer system allows the pattern to be imaged at infinity, thereby minimizing any error which might otherwise result from incorrect assumptions about the cornea position.

Abstract: The metal vessel of the present invention is characterized in that a relief type hologram or relief type diffraction grating is formed on at least a part of the vessel by coining. By forming this hologram or diffraction grating by coining, the dimensional precision or reproducibility of the hologram of diffraction grating is highly improved. The metal vessel having the hologram formed thereon is excellent in the design and decorative characteristics, and in the metal vessel having the diffraction grating formed thereon, changes of the inner pressure can be easily detected by utilizing this diffraction grating.

Abstract: In an electron holography apparatus having an electron source, a specimen holder, an electron lens system, and an electron biprism, the electron biprism is so constructed as to be rotatable about the electron optics axis. The rotation angle about the electron optics axis is commanded by the operator of the electron holography apparatus. A central wire of the electron biprism is allowed to be translated in a direction orthogonal to the electron optics axis, thus permitting the application of the fringe scanning method. The center of an aperture is selectively allowed to be aligned with that of the electron biprism to ensure that the measurement apparatus can be used selectively as either the electron holography apparatus or an electron microscope.

Abstract: A photorefractive device is provided for converting an image-bearing incoherent input beam to a high contrast coherent output beam the intensity of which varies as the square of the input intensity pattern. The device uses an incoherent image beam to write a holographic grating directly in a photorefractive medium. In one embodiment, a parallel, laterally displaced, telecentric system of lenses is used to split a quasi-monochromatic, incoherent image-bearing beam into two equal components. The two components are superimposed at the surface of the photorefractive medium to produce the hologram. In a second embodiment, the incoherent input beam is directed through a physically translating external grating to write the hologram in the photorefractive medium. The moving grating improves the diffraction efficiency of the hologram under the influence of an applied electric field and stabilizes the temporal response characteristics for signal processing.

Abstract: This invention concerns a method and apparatus of using the relatively thin holographic material of a transmission holographic optical element in such a manner whereby a narrow spectral bandwidth may be achieved. The interference fringe planes oriented through the depth of the material are interrogated by way of the edge of the holographic optical element whereby the holographic optical element is caused to respond, in use, in the manner of a relatively thick reflection holographic optical element of considerable effective thickness. The apparatus takes the form of a narrow bandwidth optical filter which is interrogated by a tightly focussed interrogating beam.

Abstract: Holograms are formed in moldable materials of varied shapes and curvatures utilizing injection molding and the like. Instead of the conventional metallizing, there can be sprayed on flakes of highly specular metal made by breaking up a thin coating of metal metallized by conventional metallizing on a removable support. Hologram on one surface of a molding that has a 100% mirror on an opposing surface, is suitable for cosmetic compact case covers or the like. Holograms can also be applied to digital compact audio discs or video discs.

Abstract: A system for interconnection of a stack of circuit boards, wherein each of at least a plurality of the circuit boards has an end region carrying one or more light transmitters or light receivers, an optical structure forming an interconnecting backplane for the circuit boards, the optical structure comprising a first surface carrying a multiplicity of hologram elements disposed to receive light beams from said light transmitters and to route said light beams to a second reflective surface where said light beams are reflected back to said hologram elements for routing to said light receivers.

Abstract: The process is disclosed for altering the wavelength response of a volume phase reflection hologram by contacting the hologram with a diffusion element containing a monomer. Monomer in the diffusion element is partially polymerized to effect a desired diffusion pattern.

Abstract: An optical system which contains multiple images comprised of two or more images at varying focal distances, which when viewed consecutively and in repetition will exercise the ciliary muscle of the eyes. The optical system may have its own power to illuminate said images. The shifting of conditions of the viewer to alternate the viewing of one image and then the other, may involve the physical movement of the user's head, the system may contain a motor coupled to rotate said system, or the configuration of the lighting source(s) shall illuminate one image and then another. The system may include a clock-timer and control of the variable speed of illumination between one optical image to another. The system may include a sound alarm to remind the viewer to utilize the holographic system.

Abstract: A hologram scale having a base substrate, a hologram film with a diffraction grating of a desired pitch exposed thereon, adhered to the base substrate, and with a protective substrate to protect the hologram film is manufactured by the following method: a hologram of a laser produced diffraction grating is formed on a holographic film to act as a scale. This film is applied on a central portion of a base substrate. Adhesives having moisture resistance are applied between the base and the protective substrates to essentially surround the hologram film positioned on the base substrate. The protective and the base substrates are sealed integrally by the adhesives, securing the hologram film therein so as to protect it from ambient environmental conditions.

Abstract: Optical detection apparatus and process which, in its optimum configuration, utilizes holographic optical elements both as a dichroic beamsplitter and as a selective notch-type barrier filter to enhance the amount of light to reach the detector while barring undesirable wavelengths from reaching the detector. The apparatus, when incorporated into a fluorescent-light detecting process, has the advantage of minimizing loss of light suffered because of a small Stokes shift, which shift occurs between the wavelength of the light transmitted to a sample target area and the increased wavelength of fluorescent light emitted from the sample for collection by a detection device.