Abstract: Embodiments of the present invention relate to holographically illuminated imaging devices including a holographic element for transforming an illumination beam into a focal array of light spots, a scanning mechanism for moving an object across one or more light spots in the focal array of light spots, and a light detector for detecting light associated with the focal array of light spots and generating light data associated with the received light.

Abstract: A laser beam (L50) generated by a laser light source (50) is reflected by a light beam scanning device (60) and irradiated onto a hologram recording medium (45). On the hologram recording medium (45), an image (35) of a scatter plate is recorded as a hologram by using reference light that converges on a scanning origin (B). The light beam scanning device (60) bends the laser beam (L50) at the scanning origin (B) and irradiates the laser beam onto the hologram recording medium (45). At this time, scanning is carried out by changing a bending mode of the laser beam with time so that an irradiation position of the bent laser beam (L60) on the hologram recording medium (45) changes with time. Regardless of an irradiation position of the beam, diffracted light (L45) from the hologram recording medium (45) produces a reproduction image (35) of the scatter plate on the spatial light modulator (200).

Abstract: Systems and methods for creating an autostereoscopic display include a holographic optical element (HOE) recorded using coherent light divided into diverging reference and object beams that illuminate the HOE from opposite sides. The object beam passes through first and second diffusers with one diffuser being a directional diffuser to more uniformly illuminate the HOE. Optic elements may be used to more closely match beam diameters and/or profiles of the recording wavelengths. Baffles may be positioned on opposite sides of the HOE with openings aligned proximate the reference beam and object beam paths, respectively, to reduce stray reflections and provide ambient air flow attenuation or damping. One or more edges of the HOE are masked to reduce or prevent stray light from entering and reflecting within the HOE during recording.

Abstract: An image display device includes an image forming device, collimating optical system, and optical device, with the optical device including a light guide plate, first diffraction grating member and second diffraction grating member which are made up of a volume hologram diffraction grating, and with central light emitted from the pixel of the center of the image forming device and passed through the center of the collimating optical system being input to the light guide plate from the near side of the second diffraction grating member with a certain angle. Thus, the image display device capable of preventing occurrence of color irregularities, despite the simple configuration, can be provided.

Abstract: A system for path compensation of multiple incoherent optical beams incorporates an optical element combining a plurality of incoherent beams to an aperture by angle using carrier frequency tilt fringes. An illumination laser is employed for reflection of an illumination beam from a target. An interferometer receives a sample of the reflected illumination beam reflected from the target and provides interference fringes. A spatial light modulator receives the interference fringes and generates a real time hologram. Relay optics are employed for transmitting the combined plurality of incoherent beams to the SLM and receiving a diffraction corrected full aperture compensated combined beam for emission to the far field.

Abstract: A laser beam generated by a laser light source is reflected by a light beam scanning device and irradiated onto a hologram recording medium. On the hologram recording medium, an image of a scatter plate is recorded as a hologram by using reference light that converges on a scanning origin. The light beam scanning device bends the laser beam at the scanning origin and irradiates the laser beam onto the hologram recording medium. At this time, scanning is carried out by changing a bending mode of the laser beam with time so that an irradiation position of the bent laser beam on the hologram recording medium changes with time. Regardless of an irradiation position of the beam, diffracted light from the hologram recording medium produces a reproduction image of the scatter plate on the spatial light modulator. The modulated image of the spatial light modulator is projected onto a screen.

Abstract: An apparatus and method for insuring the proper alignment of a detected vein pattern and a projected vein pattern are disclosed. The apparatus enhances the visual appearance of veins so that an error that can lead to improper patient care or injury can be avoided.

Abstract: Embodiments of a grey-scale holographic structure and system for generating a collimated wavefront in a compact range are generally described herein. In some embodiments, the grey-scale holographic structure comprising millimeter-wave transmissive material having a surface arranged to provide differing amounts of phase-delay to an incident millimeter-wave wavefront as the incident wavefront passes through the material. The grey-scale holographic structure may comprises a plurality of layers (N) to provide a phase total delay of lambda which results from a series tuned layers, each having a thickness of a wavelength/N. Each layer provides a predetermined amount of phase delay allowing the structure to operate as a phase-delay hologram.

Abstract: Provided in one embodiment is an apparatus for displaying an image, comprising: an input image node configured to provide at least a first and a second image modulated lights; and a holographic waveguide device configured to propagate the at least one of the first and second image modulated lights in at least a first direction. The holographic waveguide device comprises: at least a first and second interspersed multiplicities of grating elements disposed in at least one layer, the first and second grating elements having respectively a first and a second prescriptions. The first and second multiplicity of grating elements are configured to deflect respectively the first and second image modulated lights out of the at least one layer into respectively a first and a second multiplicities of output rays forming respectively a first and second FOV tiles.

Abstract: A phase mask includes a phase modulation layer that modulates a phase of different portions of incident light, differently, such that a different optical phase delay, in a range between 0 and 2? is imparted to different portions of the incident light. A hologram recording apparatus includes a light source; a signal beam optical system that divides a beam emitted from the light source into a reference beam and a signal beam, modulates the signal beam according to hologram pixel information, and radiates the signal beam onto a hologram recording medium. The signal beam optical system includes the phase mask. The hologram recording apparatus also includes a reference beam optical system that radiates the reference beam onto the hologram recording medium.

Abstract: Continuous Adjustable Pulfrich Filter Spectacles are provided with lenses with continuously changeable optical densities, so that viewing of 2D movies is optimized for visualization in natural 3D. Method and means are disclosed for the continuous Adjustable Pulfrich Filter Spectacles to perform two independent optimizations to achieve optimized 3Deeps visual effects on 2D movies. First they compute the optical density setting of the lenses for optimal viewing of 2D movies as 3D. Then they continuously render the lenses of the spectacles to these optical densities optimized for characteristics of the electro-optical material from which the lenses of the spectacles are fabricated. The invention works for both 3DTV and 3D Cinema theater viewing.

Abstract: There is provided an exposure device including: a light-emitting element array at which a plurality of light-emitting elements, that emit light that passes through an optical path of diffused light, are arrayed one-dimensionally or two-dimensionally on a substrate; and a hologram element array at which a plurality of hologram elements are formed at positions, that respectively correspond to the plurality of light-emitting elements, of a hologram recording layer disposed on the substrate, so as to diffract and collect, at an outer side of illumination regions of all of the plurality of light-emitting elements, respective lights that are emitted from the plurality of light-emitting elements respectively.

Abstract: A method of displaying a video image comprises receiving sequential image frames at a processor. Each image frame is processed to obtain a kinoform. A programmable diffractive element such as an SLM represents the sequence of kinoforms allowing reproduction of the image using a suitable illumination beam.

Abstract: A device for reducing laser speckle using a micro scanner and a holographic diffuser. The micro scanner includes a first transparent optical substrate with an input surface and an output surface and a second transparent optical substrate with an input surface and an output surface and a variable refractive index medium sandwiched between the output surface of the first substrate and the input surface of the second substrate. Transparent electrodes are applied to the output surface of the first substrate and the input surface of the second substrate. The electrodes are coupled to a voltage generator. The input surface of the first substrate is optically coupled to a laser source. The input surface of the second substrate is configured as an array of prismatic elements. At least one of the input surface of the first substrate or the output surfaces of the second substrate is planar.

Abstract: The subject matter described herein includes a curved VPH grating with tilted fringes and spectrographs, both retroreflective and transmissive, that use such gratings. A VPH grating according to the subject matter described herein includes a first curved surface for receiving light to be diffracted. The grating includes an interior region having tilted fringes to diffract light that passes through the first surface. The grating further includes a second curved surface bounding the interior region on a side opposite the first surface and for passing light diffracted by the fringes.

Abstract: A color sequential illumination device including in series: first and second light sources; a condenser lens; and a grating device. The grating device includes at least one Bragg grating. The condenser lens directs light from the first and second sources into the grating device at first and second incidence angles respectively. The grating device diffracts light from the first and second sources into a common direction. Desirably, the Bragg gratings are Electrically Switchable Bragg Gratings. In one embodiment the light sources are Light Emitting Diodes. Alternatively lasers may be used.

Abstract: For comfortable viewing of a 3-D scene at various viewing angles, a display having a large tracking range for a variable viewer distance is required. A controllable light-influencing element deflects light in coarse steps in a viewer range. Within said steps, the light is deflected by a further controllable light-influencing element continuously or with fine gradation. The light modulation device is suitable in holographic or autostereoscopic displays for guiding the visibility ranges of the image information to be displayed so as to follow the eyes of the viewers.

Abstract: An exposure apparatus includes a substrate in which plural light-emitting devices are arrayed one-dimensionally or two-dimensionally; and a hologram recording layer that is disposed on the substrate, plural holograms being recorded in the hologram recording layer by holographic interference between a first beam and a second beam such that a predetermined number of beam spots are disposed in the hologram recording layer in a predetermined array direction according to a portion of light-emitting devices, the portion of light-emitting devices being selected as emitters from the plural light-emitting devices, the beam spot being formed by a light beam of the second beam, the first beam passing through an optical path of diffusion light that passes through the emitter, the second beam passing through an optical path of convergent light that converges at a predetermined distance outside the optical path of the first beam.

Abstract: Proposed is a method of laser illumination with reduced speckling for in optical microscopy, machine vision systems with laser illumination, fine optical metrology, etc. The method comprises forming a net of planar ridge waveguides into an arbitrary configuration and providing them with a plurality of holograms having holographic elements formed into a predetermined organization defined by the shape of a given light spot or light field which is to be formed by light beams emitted from the holograms on the surface of the object or in a space at a distance from the planar ridge waveguide. Speckling is reduced by locating at least a part or all of the holograms at distances from each other that are equal to or greater than the coherence length. The geometry and organization of the holographic elements allows controlling position, focusing and defocusing of the beam.

Abstract: Proposed is a speckle-reduced laser illumination device that may be used in optical microscopy, machine vision systems with laser illumination, fine optical metrology, etc. The device comprises a net of planar ridge waveguides formed into an arbitrary configuration and having a plurality of holograms with holographic elements formed into a predetermined organization defined by the shape of a given light spot or light field which is to be formed by light beams emitted from holograms on the surface of an object or in a space and at a distance from the planar ridge waveguide. Speckling is reduced due to the fact that at least a part or all of the holograms are spaced from each other at distances equal to or greater than the coherence length. The geometry and organization of the holographic elements allow position control of the light spot and beam converging and diverging.

Abstract: Disclosed is a dispersion compensation optical apparatus including a first transmission type volume hologram diffraction grating and a second transmission type volume hologram diffraction grating. The first and second transmission type volume hologram diffraction gratings are arranged facing each other. A sum of an incident angle of laser light and an emitting angle of first-order diffracted light is 90° in each of the first and second transmission type volume hologram diffraction gratings.

Abstract: An optical effect disc, has a transparent substrate and a surface optical structure, and an optical recording media combining the optical effect disc. The surface optical structure may be a computer-generated hologram optical structure or a micro-lens array structure for showing the effect of brightening or peep prevention, or a diffraction gating structure for achieving a three-dimensional visual effect. The optical effect disc or the optical recording media may include an image forming layer for forming an image to be shown by the optical effect disc with corresponding visual effect. The optical effect disc or the optical recording media may include an adhesive layer for attaching the optical effect disc to the optical recording media.

Abstract: A means for 3D imaging takes two plane pictures of an object in different angles and respectively projects the correspondent images of the object toward users' eyes. Accordingly, the visual data would be transmitted to user's brain and integrated to construct a solid vision. A facility for 3D imaging comprises a multiple image projector consisting of a displaying unit installed on a refracting unit. Wherein, the displaying unit performs a plurality of images, and the refracting unit adopts an optical unit. Thereby, image beams generated by the displaying unit would travel through the refracting unit and deflect by a certain angle. Accordingly, the images shot from two different angles would be respectively projected into user's eyes, and a solid vision could be constructed.

Abstract: The present invention relates to a container comprising a multilayer sheet, the multilayer sheet comprising a substrate layer with an optical element being formed by a reflective microstructure, and a print layer comprising add-on material. The multilayer sheet further comprises a first area, wherein the optical element is provided, and a second area, wherein add-on material is provided and wherein no microstructure is provided, and a transition area between the first area and the second area. The transition area comprises a transition microstructure that is formed in the substrate layer, wherein the transition microstructure provides for a substantial diffuse reflection of light. The invention further relates to a method for production of a multilayer sheet with an optical element.

Abstract: A laser processing apparatus including a laser light source, a phase modulation type spatial light modulator, a driving unit, a control unit, and an imaging optical system. A storage unit that is included in the driving unit stores a plurality of basic holograms corresponding to a plurality of basic processing patterns and a focusing hologram corresponding to a Fresnel lens pattern. The control unit arranges in parallel two or more basic holograms selected from the plurality of basic holograms stored in the storage unit, overlaps the focusing hologram with each of the basic holograms arranged in parallel to form the whole hologram, and presents the formed whole hologram to the spatial light modulator.

Abstract: The invention relates to an autostereoscopic 3D display (1), comprising an illumination unit (2) having two light sources (3, 4), a light guide (5), a holographic-optical element (6) as a diffractive optical light directing element, a transparent display panel (7), and a control unit (8) for alternately synchronizing the light sources (3, 4) with a right and a left parallactic image represented on the display panel (7), wherein the light sources (3, 4) are oriented so as to irradiate light into the light guide (5) from various directions and the holographic-optical element (6) and the display panel (7) are arranged such that light emitted by the light guide is diffracted by the holographic-optical element (6) in two different directions, depending in the preferred direction of the light, and directed through the display panel (7), wherein at least one surface of he light guide (5) has a refractive surface (10).

Abstract: An integrated circuit includes a holographic recording material substantially filling a cavity in a semiconductor layer. During operation of the integrated circuit, a holographic pattern in the holographic recording is reconstructed and used to diffract an optical signal propagating in a plane of an optical waveguide, which is defined in the semiconductor layer out of the plane through the cavity. In this way, the holographic recording material may be used to couple the optical signal to an optical fiber or another integrated circuit.

Abstract: A transmission type optical element comprising a first hologram having a first surface and a second surfaces and a second hologram having a third surface and a fourth surface. The first surface of the first hologram and the third surface of the second hologram are oppositely arranged. A first light beam having a first wavelength is made to enter the first hologram from the side of the second surface. It is transmitted through the first hologram and exits the first hologram from the side of the first surface. The light beam then enters the second hologram from the side of the third surface. It is diffracted by the second hologram and exits the second hologram from the side of the third surface. The light beam then enters the first hologram from the side of the first surface and is diffracted by the first hologram.

Abstract: The present invention provides a hologram which forms a light intensity distribution on a predetermined plane by using an incident light. The hologram includes a plurality of cells configured to control both a phase of a first polarized light component of the incident light and a phase of a second polarized light component. The plurality of cells are designed to form a portion in an overlap region in which a first light intensity distribution region formed on the predetermined plane by the first polarized light component and a second light intensity distribution region formed on the predetermined plane by the second polarized light component are superposed on each other. The phase of the first polarized light component is diffused in the portion formed in the overlap region.

Abstract: A device for holographic reconstruction of three-dimensional scenes includes optical focusing means which directs sufficiently coherent light from light means to the eyes of at least one observer via a spatial light modulator that is encoded with holographic information. The device has a plurality of illumination units for illuminating the surface of the spatial light modulator; each unit comprises a focusing element, and a light means that emits sufficiently coherent light such that each of these illumination units illuminates one separate illuminated region of the surface, whereby the focusing element and the light means are arranged such that the light emitted by the light means coincides close to or at the observer eyes.

Abstract: A transceiver device that includes one or more light sources configured to emit a light beam that includes one or more different wavelengths, and includes a diffractive optical element configured to initiate one or more wavelength specific responses from the light beam to form one or more transmission light beams and to direct the one or more transmission light beams substantially towards a target; and further includes one or more sensor devices configured to receive the one or more transmission light beams and one or more reception light beams that are reflected back from the target. The diffractive optical element (e.g., a holographic element) is used in either a monostatic, bistatic or multistatic design to reduce the required size and/or number of optical elements, lasers and receivers. The transceiver device may be used in a LIDAR system in order to measure air and wind parameters at multiple altitudes.

Abstract: Provided are a virtual optical input device and a method of controlling the same. In the method, a portion of an input means such as a finger, and a portion of a shadow of the input means generated by a light source are detected through image processing. Physical variations formed between them are used to detect the touch contact of the input means, calculate the position of the input means, and input the corresponding command. Accordingly, it is possible to provide various input patterns.

Abstract: A method for manipulating a plurality of objects. The method includes the steps of providing a shaping source, applying the shaping source to create a spatially symmetric potential energy landscape, applying the potential energy landscape to a plurality of objects, thereby trapping at least a portion of the plurality of objects in the,24 potential energy landscape, spatially moving the potential energy landscape to manipulate the plurality of objects; and extinguishing the potential energy landscape, thereby causing the plurality of objects to move freely when the potential energy landscape is extinguished.

Abstract: An advanced method of and apparatus for manipulating electromagnetic spectra, which incorporates a bent tepee or bent pyramidal aligned array of conical or pyramidal inverted sections that have at least two intrinsic angles of differing values aligned co-axially. These are arranged to naturally produce a reference and object waves that impinges on and illuminate a holographic plate or recording means to produce on-axis or in-line transmission and reflection holograms, including real time display. The technology is also applicable to the detection, identification, and/or decoding of genetic material, specifically DNA and the Human Genome.

Abstract: A method for producing a security element (55) and a security element (55) in the form of a multilayered film body having a top side facing the observer. The security element (55) has a volume hologram layer, in which a volume hologram is recorded, which provides a first optically variable information item. The security element (55) has a replication layer, in the surface of which a relief structure providing a second optically variable information item is molded and which is arranged above the volume hologram layer. A partial metallic layer is arranged between the volume hologram layer and the replication layer, wherein the metallic layer is provided in one or a plurality of first zones of the security element and the metallic layer is not provided in one or a plurality of second zones of the security element.

Abstract: A waveguide 60 formed of material 62 allows propagation of image bearing light along a light pathway 64 by total internal reflection of the image bearing light. The layer of material 62 is a light transparent material arranged to allow an observer, not illustrated, to look through the layer of material 62 whilst also arranged to carry image bearing light. A grating element 66 carried within the layer of material 62 is arranged such that impinging image bearing light following the light pathway 64 is either diffracted out of the layer of material 62 as a pupil of image bearing light 68a to 68n or is reflected by either surface 70 or surface 72. The efficiency of the grating element 66 is varied along the length of the layer of material 62 to achieve the desired pupils of image bearing light 68a to 68n along the length of the layer of material 62. This results in a more even brightness of pupils of image bearing light 68a to 68n, as perceived by the observer looking through the layer of material 62.

Abstract: A projection device includes an optical element including a hologram recording medium where information is multiplexedly recorded in each position so as to allow a coherent light beam to be diffused to a plurality of regions, an irradiation device configured to irradiate the optical element with the coherent light beam so as to allow the coherent light beam to scan the hologram recording medium, spatial light modulators configured to be illuminated with the coherent light beam which is incident from the irradiation device to the hologram recording medium to be diffused to the plurality of regions, and projection optical systems, each projection optical system projecting modulation image obtained on each spatial light modulator on corresponding screen. The coherent light beam, which is incident to each position of the hologram recording medium to be diffused, is illuminated on a plurality of the spatial light modulators.

Abstract: A holographic planar concentrator of solar energy employing an array of holographically-recorded diffraction grating elements adjoining the corresponding bifacial or monofacial PV-cell. Diffracting grating elements are configured to operate in transmission and/or reflection. The array is sandwiched and, optionally, encapsulated between the two layers of structurally supporting material that are impermeable to ambient moisture. The grating elements can be blazed and the material layer in which the gratings are recorded is protected from the moisture in the ambient environment by a moisture impermeable encapsulant.

Abstract: An illumination device has an optical device and an irradiation unit. The irradiation unit has a light source emitting a coherent light beam, and a scanning device capable of adjusting a reflection angle of the coherent light beam emitted from the light source. The light source has light sources emitting a plurality of coherent light beams having an identical wavelength range, the hologram recording medium has a recording area to be scanned with each of a plurality of coherent light beams reflected by the scanning device, and the recording area has an interference fringe that diffracts an incident coherent light beam. The optical device uses the plurality of coherent light beams diffracted by the interference fringe of the recording area so that each of the coherent light beams diffracted by the hologram recording medium is superimposed on at least one portion to reproduce the image of the reference member.

Abstract: A method for producing a single-layer diffractive combiner for a head-up display having a projection unit with n light sources of ?i wavelength(s), where i=1 to n sending light towards the combiner at an angle ?p. The method includes forming interference fringes for each ?i wavelength on a photosensitive layer with an interference of two light beams from a single laser source of wavelength ?e, where the forming step is repeated n times, and each time the forming step is repeated an angle ?i between the two beams is determined according to ?i=arcsin ((?e/?i)*sin(?p)), one of the interfering beams being divergent and having a spherical wave front and the other being a plane wave, the interference of the beams generating a diffractive network with an adjustable pitch and curved contour fringe lines.

Abstract: Certain embodiments of the disclosed technology may include light reflector systems, methods, and apparatus. According to an example embodiment, a light reflector is provided. The light reflector includes a rear reflector that includes a reflective surface. The light reflector includes a lenticular optical film having a smooth surface and a structured surface. The smooth surface of the lenticular optical film is attached or disposed adjacent to the reflective surface. The lenticular optical film is configured for condensing and diffusing light.

Abstract: A method and system for manipulating object using a three dimensional optical trap configuration. By use of selected hologram on optical strap can be configured as a preselected three dimensional configuration for a variety of complex uses. The system can include various optical train components, such as partially transmissive mirrors and Keplerian telescope components to provide advantageously three dimensional optical traps.

Abstract: This invention relates to autostereoscopic display assemblies, in particular for hand-held devices such as tablets, i-Pads, mobile phones, etc., wherein a stereoscopic effect is achieved by forming light beams are emitted from the display at different angles and with different polarization. The display assembly comprises a sandwiched structure consisting of a light-guide panel and a modified liquid-crystal display that is applied onto the light-guide panel. The panel has on its outer surface a net of light waveguides for delivery of light from the light source and for uniform distribution of light over the entire surface of the display. The different polarizations and angular directions of the beams perceived differently by a viewer's left and right eyes are achieved by providing the light-distribution waveguides with holograms of two different types.

Abstract: An object of the present invention is to display a highly reproducible three-dimensional image in response to changes in the viewer's position and to easily realize the miniaturization of the system. The three-dimensional image projector includes a projection image forming disc in which a hologram recording medium is formed along a disc-shaped glass substrate, and which projects image light having directivity by causing the image light to fall incident on the hologram recording medium, and a rotational drive unit for rotationally driving the projection image forming disc along a surface of the glass substrate with the center point on the surface as a rotation center. The projection image forming disc is preliminarily recorded with a hologram by causing two laser beams as reference light and object light to simultaneously fall incident on the hologram recording medium.

Abstract: The present invention provides a computer generated hologram including a plurality of anisotropic cells having different refractive indices with respect to linearly polarized light in a first direction and linearly polarized light in a second direction perpendicular to the linearly polarized light in the first direction, wherein the plurality of anisotropic cells are made of an identical material and includes a first anisotropic cell, a second anisotropic cell, a third anisotropic cell, and a fourth anisotropic cell which have different thicknesses, and the plurality of anisotropic cells change phases of linearly polarized light in the first direction and linearly polarized light in the second direction, thereby making a first light intensity distribution formed on a predetermined plane by the linearly polarized light in the first direction different from a second light intensity distribution formed on the predetermined plane by the linearly polarized light in the second direction.

Abstract: A novel light absorbing holographic film for holographic processing is present. The holographic film includes a light absorbing film having a holographic medium disposed thereon. The light absorbing film comprises a substrate and a light absorption layer disposed on a first surface of the substrate. In certain embodiments a second light absorption layer is disposed on a second, opposing surface of the substrate. In other embodiments, a second absorption layer is disposed on top of the first absorption layer.

Abstract: A holographic replicator configured to mass-manufacture volumetric transmission holograms and including an imaging tank having a holographic master plate opposing a pneumatic absorber. When a segment of a recording film, moveable with respect to the master plate, is placed between the master plate and the pneumatic absorber, the pneumatic absorber is repositioned in space to locks the segment of the recording film between the master plate and the pneumatic absorber.

Abstract: A security Device comprises a zero order diffractive microstructure (5) buried within a substrate (3). One or more further optical structures, such as microlenses (1), may be formed on a surface (2) of the substrate (3). The further optical structures modify the optical characteristics of the zero order diffractive microstructure (5). Various alternatives or additional optical structures and methods of producing them are described in additional embodiments.

Abstract: In an optical head device which performs recording/reading of data in/from a high-density optical disc using an objective lens with a large NA, a saw-tooth shape diffraction element is used for also performing recording/reading of data in/from a conventional optical disc, such as DVD, CD, or the like. A step difference that produces an optical path length for blue light which is equal to or longer than the wavelength of the blue light and optical path lengths for red and infrared light which are shorter than the wavelengths of the red and infrared light is utilized so as to exert an inverse action on the blue light to those exerted on the red and infrared light. The effect of increasing the working distances for CD and DVD enables multiple compatibility. The optical element is integrally combined with the objective lens to perform a tracking servo following operation.

Abstract: A laser beam generated by a laser light source is reflected by a light beam scanning device, and irradiated onto a hologram recording medium. On the hologram recording medium, an image of a scatter plate is recorded as a hologram by using reference light that converges on a scanning origin. The light beam scanning device bends the laser beam at the scanning origin and irradiates it onto the hologram recording medium. At this time, scanning is carried out by changing the bending mode of the laser beam with time so that the irradiation position of the bent laser beam on the hologram recording medium changes with time. Regardless of the beam irradiation position, diffracted light from the hologram recording medium reproduces the same reproduction image of the scatter plate at the same position. An illumination spot in which speckles are reduced is formed on the light receiving surface of an illuminating object by the reproduction image of the hologram.