Abstract: An apparatus for making a high quality reflection type holographic optical element (HOE) using a single input laser beam, including a reflective mirror, a holographic photoplate having a photo emulsion layer on a surface nearest the reflective mirror, a cassette for retaining the reflective mirror and the holographic photoplate, and a refractive index matching fluid containing a light absorbent dye for absorbing an input laser beam. The cassette is immersed in the fluid so that fluid is retained between the photo emulsion layer of the holographic photoplate and a reflective surface of the reflective mirror. Parasitic interference patterns are suppressed by heating the refractive index matching fluid with the input laser beam, which causes a shift of the phase of the parasitic beams with respect to the phase of the beams responsible for recording the HOE. If the photo emulsion layer of the holographic photoplate consists of a dichromated gelatin (DCG), then a photo sensitizer agent (e.g.

Abstract: The present invention relates to a method and an apparatus for holographically recording periodic or quasi-periodic features of a mask in a holographic recording layer. In holographic lithography the object beam is directed to the first substrate bearing a holographic recording layer such that it passes the mask substrate and interferes with a reference beam in the recording layer to form a hologram of the mask pattern. According to the new method the object beam is directed to the second substrate at an off-axis angle and the wavelength used and/or the angle of incidence of the object beam are selected according to the period of the features to be recorded such that essentially just the zero and one of the first diffraction orders are present for forming the hologram.

Abstract: A method for producing a hologram recording an interference fringe formed by an object light and a reference light on a photosensitive dry plate, and the object light either having diffusing and scattering characteristics or being passed through an optical diffusion body, mainly includes the following steps: In a first step, a ratio &eegr;RO/&eegr;OO of a first diffraction efficiency &eegr;OO and a second diffraction efficiency &eegr;RO, is calculated. The diffraction efficiency &eegr;OO is dependent on two object light beams. The efficiency &eegr;RO is dependent on the object light and the reference light. In a second step, the intensity EO of the object light and the intensity ER of the reference light is adjusted in such a way that the ratio &eegr;RO/&eegr;OO is set to at least 10 and the efficiency &eegr;OO does not exceed 5%.

Abstract: An improved process for holography is provided, in which the reference beam used for storage and readout has a correlated phase content. In particular, it was found that reference beams having random phase content limited the attainable storage density and the accuracy of readout of stored holograms due to uncontrolled fluctuations in the correlation selectivity. By contrast, a reference beam having correlated phase content provides accurate shift selectivity, the ability to tailor the reference beam spectrum to minimize crosstalk between neighboring holograms, and mitigation of limitations inherent in the holographic system or holographic medium. Improved storage density and readout accuracy are thereby attained.

Abstract: A holographic shrink wrap element containing a shrink wrap film and a layer on the shrink wrap film, wherein the layer contains a holographic image. A process for preparing a holographic shrink wrap element includes providing, in the following order, a holographic polymer film having a holographic surface, a layer on the holographic surface and a shrink wrap film, and removing the holographic polymer film, leaving the holographic image on the layer.

Abstract: Holographic memory including a beam source for emitting a beam, a beam splitter for splitting the beam into a reference beam and an object beam, a hologram memory unit for recording information designated to a cell when the reference beam and the object beam are incident thereto at a time, and reproducing the information recorded before when only the reference beam is incident thereto, a first optical path changing unit for directing the reference beam to be incident to the hologram memory unit at an arbitrary angle for recording and reproduction of the information, including a first deflector for deflecting the reference beam to an arbitrary angle, a second deflector for re-deflecting the reference beam deflected at the first deflector in a vertical direction, and a telescope having at least one composite HOE(Holographic Optical Element) for directing the reference beam re-deflected at the second deflector to be incident to the hologram memory unit, and a second optical path changing unit for adjusting an op

Abstract: A method for encoding zero-order phase-only holograms, and the holograms so encoded. The amplitude and phase of each point of a discrete mathematical transform, such as a Fourier transform, of an image to be encoded, are encoded as regions of a corresponding pixel of a transparent filter, with suitably selected fractional areas and optical path lengths. The various optical path lengths may be created by manipulating the filter's index of refraction, or by manipulating the thickness of the filter, preferably by etching. Various encoding schemes are presented, appropriate to etching systems with low lateral resolution, to etching systems with high lateral resolution but depth resolution limited to a discrete number of depths, and to etching systems with limited resolution both laterally and in depth.

Abstract: A method for producing a hologram recording an interference fringe formed by an object light and a reference light on a photosensitive dry plate, and the object light either having diffusing and scattering characteristics or being passed through an optical diffusion body, mainly includes the following steps: In a first step, a ratio .eta..sub.R0 /.eta..sub.00 of a first diffraction efficiency .eta..sub.00 and a second diffraction efficiency .eta..sub.R0, is calculated. The diffraction efficiency .eta..sub.00 is dependent on two object light beams. The efficiency .eta..sub.R0 is dependent on the object light and the reference light. In a second step, the intensity E.sub.O of the object light and the intensity E.sub.R of the reference light is adjusted in such a way that the ratio .eta..sub.R0 /.eta..sub.00 is set to at least 10 and the efficiency .eta..sub.00 does not exceed 5%.

Abstract: A holographic medium uses a photosensitive polymer medium. The shelf life of the photosensitive polymer medium is improved by hermetically sealing the polymer between glass plates. The hermetic seal is designed so that high T.sub.g materials, or solder, can be used as the sealant without damage to the polymer already contained between the plates. The hermetic seal comprises metal foils attached to the plates with the edges thereof extending away from the plates in tab-like fashion. The foils are attached prior to filling the assembly with polymer. After filling, the outer edges of the foil tabs are the sealed with local heating away from the site of the polymer, or crimped using mechanical crimping.

Abstract: A display panel having compensation using holographic birefringent films. Due to the natural birefringence of liquid crystals, contrast suffers when a liquid crystal cell is viewed at an oblique incident angle. Compensation devices made of birefringent media are used to correct this deficiency. The compensation devices include at least one film, the birefringence of which is induced by the recording of a volume hologram consisting of parallel fringes. The choice of the optical birefringent axes depends only on the orientation of the fringes so that it is easy to achieve compensation using uniaxial films which are inclined with respect to the plane of the film.

Abstract: A method for fabricating an article, comprising the steps of grasping an outer surface of a first substrate with a first holder, whereby the outer surface of the first substrate is held to an inner surface of the first holder; grasping an outer surface of a second substrate with a second holder, whereby the outer surface of the second substrate is held to an inner surface of the second holder; arranging the inner surfaces of the first and second holders to face one another in a selected angular relationship; disposing an adherent on one or more surfaces selected from an inner surface of the first substrate and an inner of the second substrate; moving the first and second holders toward each other such that the inner surfaces of the first and second substrates contact the adherent; and at least partially curing the adherent while the inner surfaces of the first and second holders are in the selected angular relationship to form a multilayer article, wherein after removal of the first and second holders the at

Abstract: A method and apparatus for making holograms includes a technique for exposing a film substrate or other light-sensitive medium to consecutive two dimensional images, together representative of a physical three-dimensional system, to generate a three dimensional hologram of the physical system. Low beam ratios are employed to superimpose multiple (20-300) images on the substrate. Each image is relatively weak, but the combination of the series of weak images ultimately appears as a single clearly defined hologram.

Abstract: A method and system are disclosed for recording and displaying grazing-incidence (i.e., steep reference beam angle) holograms supported on a substrate having thin edge-illuminatable geometry. The system and process use thin edge-illuminated substrates that facilitate optimal coupling of the reference light beam at steep angles approaching grazing incidence, while maximizing the contrast of the slanted fringe structures thereof. Different recording techniques are employed when the index of refraction of the substrate is greater than that of the recording medium, than when the index of refraction of the substrate is less than that of the recording medium. A recording and playback system of complementary design is provided for recording slanted-fringe volume holograms under relaxed conditions, without compromising the light diffraction efficiency of the holograms under different playback conditions.

Abstract: A positive unit magnification reflective head is used to back-reflect a primary light beam, for storing reflection microholograms at the coincident foci of the primary and reflected beams. Imaging the primary beam focus onto itself at positive unit magnification allows increasing system tolerance to tilts and transverse misalignments between the primary and reflective heads. Holograms are stored at multiple depths in a holographic storage medium. Tunable-focus primary and reflective heads are positioned on opposite sides of the storage medium. The reflective head images each storage location onto itself at positive unit magnification. Suitable reflective heads include: two lenses in an f-2f-f configuration and a planar mirror; a lens and a corner cube; a thin lens and a thick lens with a coated reflective back surface; and a thin lens and a back-coated gradient-index (GRIN) lens.

Abstract: The invention provides a hologram-recording subject plate comprising a block and a variety of subjects fixedly contained therein, which ensures easy, stable yet continuous recording of a multiplicity of identical holograms or different holograms reconstructible by illuminating light as is the case with a hologram-replicating method, a hologram-making method using the same, and a hologram-recorded article. The subject plate comprises a transparent solid block 5 and a hologram-recording subject S contained therein. A photosensitive material film 1 is applied directly onto one surface of the subject plate, and the subject plate is then irradiated with laser light 7 through the photosensitive material film 1. Such simple operation enables a multiplicity of identical holograms to be recorded in an easy, stable yet continuous manner.

Abstract: A decorative construction 10 for attachment to a vertical surface wherein the decorative construction 10 includes a main image unit 11 comprising a generally elongated rectangular sheet of decorative paper 20 and a plurality of holographic image units 12 adapted to be operatively associated with the front face 23 of the sheet of decorative paper 20.

Abstract: Reflective image-providing displays illuminated with chromatically-adjusted holographically diffused light are provided. In one particular and preferred embodiment, a liquid crystal display component is presented comprising a liquid crystal display element backed with a reflective transmission holographic diffuser. Chromatic adjustment is effected by the inclusion in said liquid crystal display component of a compensatory filter layer of relatively low density designed to restore the ambient color balance of input light, the balance being otherwise upset by transit through said liquid crystal display element. Achromatically illuminated images of good contrast are displayed and viewed from the liquid crystal display component under ambient lighting conditions.

Abstract: A holographic memory device includes: a hologram memory part for information recording by using a reference beam and an object beam, the hologram memory part having a plurality of cells; a first optical path modifying part having a fine adjustment element that adjusts the reference beam's path so as to be incident on the hologram memory part at a specific angle for information recording and reconstructing, and that adjusts the reference beam's path so as to be incident on the hologram memory part at a desired angle for information reconstructing when an angle of incidence of reference beam for information reconstructing doesn't coincide with that of reference beam for information recording; and a second optical path modifying part that adjusts the object beam's path so as to be incident on the hologram memory part for information recording.

Abstract: A holographic spectroscope for a two-motor reflection system for generating scanning patterns in which a light beam is first reflected by a first reflector connected to a first motor electrically connected to a first control circuit. A second reflector for reflecting the light beam reflected by the first reflector is connected to a second motor electrically connected to a second control circuit and to form scanning patterns. A holographic spectroscope for diffracting the scanning patterns is mounted in the optical path of the light beam from the second reflector. Therefore, the scanning patterns can be improved to be more variable.

Abstract: A light source module with two wavelengths that is adapted to generate laser beams different in wavelength. In the light source module, a hologram optical element (HOE) is used to allow a first laser beam generated at a first light source and a second laser beam generated at a second light source to progress along same path. The HOE diffracts the second laser beam to change a progressive path of the second laser beam into that of the first laser beam. The first light source generates the first laser beam having a different wavelength from the second laser beam generated at the second light source.

Abstract: A fingerprint sensor having a holographic phase grating glued on one right angle surface of a prism is described where a light source oriented normally relative to the hypotenuse surface of the prism illuminates an interface of the grating and finger surface. Incident light rays are refracted and absorbed where ridges of the finger surface contact the grating surface, whereas light rays are totally internally reflected in areas between and pores in finger surface ridges not in contact the grating surface. The reflected light rays, diffracted by the holographic phase grating, propagate normally (.perp.) back into the right angle prism where they are reflected normally (.perp.) out the remaining right angle surface of the prism by a second total internal reflection at the internal hypotenuse surface of the prism. The reflected light rays emerging from the sensor contain high contrast, detailed images of the ridges and valleys of the finger surface including pores in the ridges, i.e.

Abstract: An optical scanning holography system which requires only a two dimensional scan to record three dimensional information from a fluorescent specimen wherein the optical scanning holography is based on scanning the specimen with a Fresnel zone pattern and detecting and decoding the fluorescent light reflected from the specimen. The flourescent light reflected from the specimen contains three dimensional information about the specimen so that once the fluorescent light is detected and decoded a three dimensional image of the specimen can be obtained and displayed using only the two dimensional scan.

Abstract: The invention features methods and systems for thermally fixing or erasing a laser-induced hologram in a photorefractive material, for example, by directing laser radiation having a wavelength through a thickness of the photorefractive material containing the hologram, wherein the wavelength is selected such that the photorefractive material absorbs a portion of the laser radiation and transmits another portion of the laser radiation. The transmitted laser radiation can be redirected back through the hologram, wherein both the laser radiation directed and redirected to the hologram are sufficiently absorbed by the photorefractive material to thermally fix or erase the hologram.

Abstract: Method for producing a of a transparent type hologram screen of an wide visible range. A photosensitive member and a light source of a reference light are arranged on the same side of the light diffusing body. A light source of an object light is arranged on the opposite side of the light diffusing body, so that the light is transmitted through the light diffusing body to generate a object light. A light from a light source of a reference light is reflected at the light diffusing body or a member such as a half mirror or a transparent, reflective hologram element arranged at a front side of the light diffusing body.

Abstract: Surface relief holograms are prepared by directly impressing them into aluminum and other hard metal substrates, without the need to preheat or otherwise soften the substrate. A holographic embossing shim is prepared from a master and possesses a unique combination of surface configuration, hardness, and strength. The embossing shim can be mounted on a cylindrical support. In one embodiment, the shim is used to emboss a hardenable material, which is later hardened to form a tool.

Abstract: A method and an apparatus for increasing detection signal-to-noise ratio, while reading out a hologram from a holographic storage medium, are disclosed. The hologram is written by interfering a write reference beam with an object beam. The method comprises the steps of (1) effecting multiple sequential hologram-read operations using multiple read reference beams separated from each other by a separation angle; (2) shifting the detector array contents in between hologram-read operations such that the data signal patterns incident on the detector array are approximately identical but the incident scatter noise patterns are uncorrelated; and (3) integrating the multiple hologram readouts electronically on the detector array. The apparatus comprises a laser source, a beamsteerer, a detector array and a shifting device.

Abstract: A decorative optical display (20) utilizing a reflective diffraction grating (94) or a transmissive diffraction grating (304) and a plurality of polychromatic light sources (60) disposed around perimeter (106) of the reflective diffraction grating or perimeter (314) of the transmissive diffraction grating. The light sources are disposed so as to the illuminate the reflective or transmissive diffraction grating at an oblique angle (204) or (328), respectively. The oblique illumination of the reflective or transmissive diffraction grating prevents a viewer (200) from seeing undiffracted light rays (212) or (336) emanating from the light sources, which can detract from the appeal of the optical display pattern (250). The reflective or transmissive diffraction grating may be flat or curved and may be supported by a support member (90). Further, the reflective or transmissive diffraction grating may have either a single or multiple axes.

Abstract: Light dispersive insulated glazing units are disclosed. The light dispersive insulated glazing units comprise two lites of glazing material, spaced apart from and opposing one another and a visible light dispersive film, such as a hologram or diffraction grating, interposed between confronting surfaces of the lites. Methods for producing these light dispersive insulated glazing units are disclosed, as well.

Abstract: The invention relates to a sensor (9) comprising a hologram (17) supported on or within a holographic support medium (10).A species to be detected is reactive with a substance disposed throughout, the sensor (9). Optionally, a chemical reactive with a species to be detected or a specific binding conjugate of a species to be detected is disposed throughout part of or all of the sensor (9).The resulting reaction(s) cause(s) variation(s) in the hologram (17) or holographic support medium (10) which in turn varies one or more optical characteristic(s) of the hologram (17).The variation in the optical characteristic(s) of the hologram (17) and/or the holographic support medium (10), preferably give(s) rise to a wavelength shift in incident radiation. The variation of the optical parameter is related to the species to be detected.The advantages of the sensor are that it is cheap, easy to manufacture and, once calibrated, reliable and robust.

Abstract: The present invention uses a hologram superimposed on a traditional picture such as a photograph or printed picture. The hologram is more viewable at certain angle ranges than at others. This allows the hologram image, the picture or a combination of both to be seen at different angles, thus allowing different visual effects. In a preferred embodiment a pre-made multi-channel hologram is superimposed over a user's portrait photograph taken in a photo booth. The multi-channel hologram is aligned with the photograph so that by varying the viewing angle of the combined picture and hologram an interesting, entertaining or educational effect, such as transforming, or "morphing," the user's face into another face or image, is seen. For example, a portrait photograph of the user can morph into an animal's face, a skeleton, a scary beast, etc. The morphing, or transformation, effect is easily achieved by insuring that the hologram image is substantially aligned with the portrait photograph.

Abstract: A duplicating photosensitive material film is brought into close contact with an ND glass reduced in thickness so as to become flexible or a flexible sheet or an ND glass coated with a cushioning layer through an optical contacting liquid containing a surface active agent. In addition, a spacer is interposed between a hologram original plate and a duplicating photosensitive material, and a space defined by the spacer is filled with an optical contacting liquid, thereby regulating the thickness of the optical contacting liquid layer with the spacer. Therefore, when pressure is applied, the optical contacting liquid is uniformly pressed, so that it can be made uniform and thin in thickness. Accordingly, it is possible to prevent a failure of duplication of a hologram image due to undesirable flow of the optical contacting liquid.

Abstract: An antiglare inner mirror includes a housing which is supported by a stay and is capable of inclining by an inclining device. A mirror main body is mounted on a front opening portion of the housing. The mirror main body includes a front glass, a hologram element and a seal glass bonded integrally together. A reflecting film is formed on the rear surface of the seal glass. The hologram element consists of a reflecting type hologram element having a reflecting plane made of interference fringes which is arranged non-parallel to the front surface of the hologram element. Incident light from outside is reflected both by the reflecting film and by the interference fringes of the hologram element to form rays of light reflected in different directions.

Abstract: A warning indicator that comprises a lamp hidden adjacent to the roof of a vehicle, such as a school bus, and a transmission hologram decal containing a hologram that is mounted on a front or rear window of the vehicle. The lamp projects a beam of light downward onto the transmission hologram decal where it is diffracted by the hologram into a predetermined angular field of view at the front of rear of the vehicle. The hologram projects an image, such as the word "STOP", for example, to warn drivers of other vehicles that the vehicle, such as the school bus, for example, has come to a stop. The hologram is preferentially designed to have an asymmetrically-shaped field of view.

Abstract: The present invention relates to holographic multicolor optical elements for use as multicolor filters in liquid crystal displays and methods of making the elements. The elements can be used as multicolor reflective or transmission filters The elements can have one, two, three or more holographic recording film layers Each layer comprises at least first and second pixel volumes containing holographic mirrors and preferably third pixel volumes containing a holographic mirror.

Abstract: An optical device for generating a signal based on a distance of an object from the optical device. The optical device includes a first polarizer, a birefringent crystal positioned optically downstream from the first polarizer, and a second polarizer arranged optically downstream from the birefringent crystal. The second polarizer creates a pair of interferograms by adjusting a phase of the light. Two outputs are generated by separately integrating an amount of light of at least a part of each of the pair of interferograms. Finally, the two outputs are combined such that the signal, depending only on the distance between the object and the optical system, is obtained.

Abstract: A holographic security label and automated reading machine for marking and subsequently authenticating any object such as an identification badge, a pass, a ticket, a manufactured part, or a package is described. The security label is extremely difficult to copy or even to read by unauthorized persons. The system comprises a holographic security label that has been created with a coded reference wave, whose specification can be kept secret. The label contains information that can be extracted only with the coded reference wave, which is derived from a holographic key, which restricts access of the information to only the possessor of the key. A reading machine accesses the information contained in the label and compares it with data stored in the machine through the application of a joint transform correlator, which is also equipped with a reference hologram that adds additional security to the procedure.

Abstract: Disclosed are a hologram unit of an optical pickup which has a main hologram and auxiliary alignment holograms around the main hologram thereof and a method of attaching a hologram plate of the optical pickup comprising the steps of: illuminating an object with an LD; forming an LD radiant point on a monitor through a microscopic lens, and a plurality of radiant points around the LD radiant point by auxiliary alignment holograms; and aligning the LD with the hologram plate by moving the hologram plate so as to form the LD radiant point in the center of the plurality of radiant points.

Abstract: The invention is intended to represent a three-dimensional image of an object just as observable from a viewing point, allowing representation of a semi-transparent image on the condition that its rear side may not transparently visible. A three-dimensional image display device according to the present invention is composed essentially of a laser light source, a modulator, an X-Y deflector, a control computer, an image data memory, a moving flat screen and a projection lens. The screen is constructed of a large number of pixels (e.g., 100 by 100 pixels) and each of the pixels is composed of a large number of diffraction elements (e.g., 5 by 5 diffraction elements). On the basis of three-dimensional image data and desired view-point data, both control and image-data preparing computers perform ON-OFF control of laser radiation onto diffraction elements having different reflection directions to determine displaying condition of a pixel composed of said diffraction elements.

Abstract: A record carrier (e.g., an identification card) of the type containing machine-readable representations of data, wherein the record carrier comprises a substrate, a first pattern of machine-readable indicia applied to one surface of the substrate, and a hologram containing machine-readable data disposed on one surface of the substrate. The information represented by the machine-readable indicia and the machine-readable data are related to one another so as to enable a user to verify the authenticity of the record carrier by comparison of the indicia and the data.

Abstract: A plurality of hologram elements are simultaneously exposed to a constructing light while they are arranged in the form of a stack, so that the incident beam can be uniform within the exposure area. The plurality of hologram elements should be transparent to the constructing light.

Abstract: A method and device for measuring the mobility distribution of particulate elements using incoherent light holography, where the particulate elements are optically labeled. An elementary hologram is formed for each particulate element at a series of periodic moments representing the transfer function as a function of the instantaneous position of that element. The transfer function is modulated by a specified periodic transfer function for labeling each simple hologram and for generating conjugate elementary holograms integrated at each moment for forming a compound velocity hologram containing coded information for each particulate element. Each compound velocity hologram is decoded to obtain specified mobility information.

Abstract: A holographic recording apparatus includes first and second light sources for respectively generating first and second light beams. A mask is located in front of a hologram recording material and has an aperture. Interference fringes are recorded in a hologram cell on the hologram recording material corresponding to the aperture. A movement mechanism supports the hologram recording material masked by the mask and relatively moves the hologram recording material with respect to the mask in predetermined directions so that an interference pattern is formed in an area on the hologram recording material. A spatial frequency changing mechanism changes incident angles of the first and second light beams with respect to the mask.

Abstract: A substrate bears holographic imagery, selected portions of which are covered by non-holographic imagery printed in predetermined geometric registry with the holographic images. Multiple replicas of this interactive graphic work are mass-produced by embossing an array of the holographic imagery into a substrate in roll form, together with eyemarks located periodically along the roll. Using these eyemarks, the roll is optically sheeted and the non-holographic imagery then printed on the holographic substrate.

Abstract: Device for the detection and processing of optical radiations, comprising at least one quantum well having asymmetric composition, said well consisting of a stack of layers of materials having differing gaps.

Abstract: A method of choosing an angle between a reference beam and a signal beam in a holographic storage apparatus is presented. The angle between the reference and signal beams can be optimized in light of crosstalk, scattering and wavelength seperation considerations.

Abstract: The invention provides a hologram-recording subject plate comprising a block and a variety of subjects fixedly contained therein, which ensures easy, stable yet continuous recording of a multiplicity of identical holograms or different holograms reconstructible by illuminating light, , a hologram-making method using the same, and a hologram-recorded article. The subject plate comprises a transparent solid block and a hologram-recording subject contained therein. A photosensitive material film is applied directly onto one surface of the subject plate, and the subject plate is then irradiated with laser light through the photosensitive material film. Such simple operation enables a multiplicity of identical holograms to be recorded in an easy, stable yet continuous manner.

Abstract: A method of providing secure identification for an article, including: providing on the article a diffraction grating strip including a pattern of a series of diffraction grating elements, each the diffraction grating element to diffract light, from a light source, in one of at least three selected different planes; serially illuminating the diffraction grating elements, detecting changes in plane of diffracted light as the diffraction grating elements are serially illuminated, and generating first information representative of the changes in plane; storing the first information representative of the changes in plane; subsequently, serially illuminating the diffraction grating elements, detecting changes in plane of diffracted light as the diffraction grating elements are serially illuminated, and generating second information representative of the changes in plane; and then, comparing the first and second information to determine the authenticity or not of the article.

Abstract: Replicas of a surface relief hologram, or other light diffraction pattern, are coated with a transparent material having substantially the same refractive index as the holograms to conform to the surface relief patterns and thus hide the hologram. The coating is pealed by hand off of the surface relief pattern in order to reveal an image visible in light reflected from the hologram. Such hidden holograms can be attached to a greeting card to reveal a greeting when the coating is removed, attached to pages of magazines or books to carry an advertising message, and the like. Other uses include making lottery tickets or other indications of a prize from such holograms, since the indication of any prize won by the holder remains hidden until the coating is pulled off, even though the coating is optically transparent.

Abstract: Method and apparatus are provided for a general purpose photonic computer. A data signal is input through an encoder to encode such signal with an instruction. The encoded signal is transmitted by means of a laser beam to an input buffer where it interferes with a reference beam so as to form an interference pattern therein as a hollogram, IPH. A read beam is directed through the IPH and through a decoder which reads the instruction as having, e.g. an OP Code, data source and destination. The decoded instruction is forwarded on the read beam to ALU spin media which respond to the instruction by flipping spins between >2 energy levels, in one or more sequences of data patterns which are read or measured by one or more sensors. Such sensors can be one or more of RF, microwave or optical sensors, which sensors output radix >2 data signals for, e.g. storage, display or further processing as desired.

Abstract: The method for forming a fine pattern on a substrate disclosed includes a step of preparing a hologram having a pattern, a step of irradiating material waves (de Broglie waves) such as neutral beams, ion beams and electron beams on the hologram, and a step of imaging the pattern on the substrate with the material waves being interfered by passing through the hologram. The light source has a source that emits a beam having a coherent wave front. Since the fine patterns are formed by utilizing the interference of material waves, the minimum processing precision can be enhanced to the extent of the wavelength of the material wave.