Abstract: A color separating prism is disclosed for use in an electronic imaging systems such as a video or digital still-image camera. The prism separates an incoming light beam into red, green and blue light components and directs the separated light components onto adjacent imaging sensors. Beam-splitting interfaces of the prism are optically configured to admit approximately ten to twenty percent of a violet light contained in the incoming light beam into the red color channel. The prism may beneficially be optically coupled to a light-rejecting filter or mirror which rejects undesired far-red, far-violet and blue-green components of the light beam. In this manner, the resultant red, green and blue channels approximate a set of substantially non-negative color matching functions to facilitate highly colorimetrically accurate color imaging and thereby reduce or eliminate the need for post-imaging color correction.

Abstract: An optical device includes (a) a dichromatic mirror composed of a vitreous substrate having a front surface and a rear surface; and a coating provided on the vitreous substrate composed of a three-layer stack including a semiconductor layer composed of a semiconductor material having a refractive index of more than 3.0, a layer composed of a material having an intermediate refractive index in the range 1.9 to 2.8, and a layer composed of a material having a low refractive index in the range 1.2 to 2.0, wherein the refractive indices of the materials of intermediate and low refractive index differ by at least 0.2, and wherein the dichromatic mirror has a luminous transmittance of at least 20% and a luminous reflectivity of at least 40%; and (b) radiation detecting means positioned on the side of the rear surface of the vitreous substrate.

Abstract: Structured materials for photonic devices, at wavelengths of X-ray, ultraviolet, visible, infrared and microwave radiation, can be made using layer growth techniques. Such a structure can be made layer by layer, by homogeneous deposition followed by localized modification for refractive index differentiation. Alternatively, the structure can be made by simultaneous growth of regions whose refractive index differs. The structures can be used as selective bandpass filters, and in photovoltaic solar cells, for example.

Abstract: A polarizing beam splitter for splitting a non-collimated light beam of a given wave length into two sub-beams, each of a different state of polarization, has a substrate provided with a polarizing stack of thin layers and a compensating means for compensating retardation of the light beam occurred in passing through the polarizing stack.

Abstract: A beam splitter for use in a projector is provided with a first transparent base; a second transparent base; and a polarizing multilayered film placed between the first and second transparent bases. The polarizing multilayered film includes high refraction layers each having a refractive index n.sub.H and low refraction layers each having a refractive index n.sub.L lower than the refractive index n.sub.H the high refraction layers and the low refraction layers being alternately laminated one another. The refractive index n.sub.H and the refractive index n.sub.

Abstract: A filter system for reflectively blocking laser radiation in the visible spectrum includes a multilayer interference structure arranged for reflectively blocking a continuous band of wavelengths including the laser radiation and transmitting other wavelengths in the visible spectrum. The filter system is arranged to control transmission of the other wavelengths of the visible spectrum such that the filter system has an essentially neutral transmission color and maximum photopic transmission consistent with the band of wavelengths reflectively blocked.

Abstract: A light beam-splitting optical component comprising an optical film formed from a layer of a first polymeric material and a layer of a second polymeric material wherein the refractive index of the first material in a first in-plane direction (x) is different from the refractive index of the second material in the first in-plane direction and wherein the difference in the refractive indices of the first material and the second material in a second in-plane direction (y) is the same sign as the difference in the refractive indices of the first material and the second material in the thickness direction (z), such that light polarized in the plane containing the x-axis is reflected from the component and light polarized in the plane containing the y-axis is transmitted through the component.

Abstract: A light pattern generator includes a reflective layer absorptive to infra-red radiation from which a desired pattern has been removed to allow passage of a light beam in the shape of the pattern. A method for making a light pattern generator includes forming a layer of reflective material on a transparent substrate and ablating a portion of the layer with a laser to create a desired pattern.

Abstract: A thin film polarizing device has first and second light transmissive substrates in the form of prisms and a plurality of thin film layers disposed between the prisms. The thin film layers and have predetermined thicknesses and refractive indices which allow unpolarized incident light to be separated into s-polarized and p-polarized light beams. Both frustrated total internal reflection and thin film interference are simultaneously employed to allow s-polarized light to be transmitted and p-polarized light to be reflected over a wide range of wavelengths and angles of incidence. The polarizing device may be used as a polarizer or a polarizer beam splitter.

Abstract: A birefringent material have two major parallel surfaces and a method of making such a material, wherein the said material comprises plural identical uniaxial birefringent polymeric films, each of said uniaxial films having an optical axis, or comprising plural identical biaxial birefringent polymeric films, each of said biaxial films having an acute bisectrix of the optical axes, wherein the material is formed from a stack of said films, with the optical axes or the acute bisectrixes of the films in the stack being aligned, and wherein said stack has been cut or skived at an angle to the optical axes or the acute bisectrixes thereof, such that when incident light passes through said material in a direction perpendicular to said major surfaces of the material, the incident light having a first plane of polarization is displaced relative to the incident light having a second plane of polarization, the first and second planes of polarization being perpendicular to each other.

Abstract: A beamsplitter (70) for separating a beam of light (48, 90, 92) into three frequency bands (94, 96, 98) corresponding to a first color (94), a second color (98), and a third color (96) adapted for use with a beam of white light (92). The inventive beamsplitter (70) includes first (78) and second (80) surfaces for reflecting the first color of light (94) and for transmitting the second color of light (98). A third (82) and fourth (84) surface reflect the second color of light (96) and transmit the third color of light (98). A glass support structure (72) supports the first (78), second (80), third (82), and fourth (84) surfaces in a predetermined configuration. The configuration is chosen so that the first color of light (94) is directed in a first direction (94), the second color of light (96) is directed in a second direction (96), and the third color of light (96) is directed in a third direction (96).

Abstract: This system for illuminating a liquid-crystal screen comprises a light source which emits an unpolarized light beam (F). A polarizing splitter device (PBS) receives this unpolarized light beam and retransmits, onto the liquid-crystal screen, a first and a second beam (F1, F2) which are polarized in the same polarization direction. The axes of the two beams make a defined angle (2.beta.) between them. A matrix of microlenses is provided with one microlens (.mu.L) for at least two adjacent picture elements (EL1, EL2) in the liquid-crystal screen. Each microlens directs that part of the first beam which it receives onto one (EL1) of the two picture elements and that part of the second beam which it receives onto the other picture element (EL2).

Abstract: A polarizing type optical apparatus has a first polarizing element disposed in a path of an incident luminous flux produced by a light source and a second polarizing element disposed in the path of a luminous flux reflected from the first polarizing element.

Abstract: A polarizing beamsplitter includes a gradient index film, such as a rugate filter, embedded in an optical medium. The rugate filter is comprises a thin film having a sinusoidal variation in refractive index through its thickness. The embedding medium may include a pair of prisms with the rugate filter between joining faces of the prisms. The rugate filter is embedded so that an incident beam in the embedding medium forms an angle with respect to a normal from the plane of the rugate filter. Embedded at a non-orthogonal angle, the rugate filter is highly transmissive for both the p- and s-polarized broadband components of the incident beam. The beamsplitter is highly reflective, however, at an s-polarization narrow wavelength reflection band determined by the refractive index variations of the rugate filter. Polarizing beamsplitters may be fabricated with multiple reflection bands, including reflection bands in spectral regions other than the visible spectrum.

Abstract: A system (50) for separating and combining frequency bands (64, 74, 78) from a beam (62) of electromagnetic energy adapted for use with a beam of white light (62) having a first (64), second (74) and third (78) frequency band. The inventive system (50) includes a first surface (58) for transmitting the first frequency band (64) and reflecting the second (70, 78) and third (70, 74) frequency bands. A second surface (60) reflects the second frequency band (74) and transmits the third (78) frequency band. A transparent support structure (52, 54, 56) supports the first surface (58) and the second surface (60) in a pre-determined orientation that provides for a low angle of incidence (66, 72) of electromagnetic energy impinging on the first surface (58) and the second surface (60) to minimize undesirable polarization effects. In a specific embodiment, the angle (66, 72) is 22.5 degrees.

Abstract: Highly efficient diffusely reflecting multilayer mirrors diffusely reflect light incident upon them. Highly efficient diffusely reflecting multilayer polarizers diffusely reflect light of one polarization while diffusely transmitting the other polarization. The diffusely reflecting mirror includes a light diffusing element and a multilayer mirror element. The diffusely reflecting polarizer includes a light diffusing element and a multilayer reflective polarizing element.

Abstract: An optical thin film for an optical element is disclosed, which includes at least one layer containing at least one compound selected from the group consisting of MoO.sub.3 and WO.sub.3. A material for use in evaporation coating to prepare a thin film includes a mixture of at least one compound selected from the group consisting of MoO.sub.3 and WO.sub.3 and another dielectric. A further optical thin film includes a substrate and superimposed thereon are alternate layers. One such alternative layer having a high refractive index, and composed of a material containing at least one compound selected from the group consisting of MoO.sub.3 and WO.sub.3. Another of such alternative layers having a low refractive index, and composed of SiO.sub.2. Another thin film includes a substrate and, superimposed thereon, at least one dielectric layer. The at least one dielectric layer being at least one layer containing at least one compound selected from the group consisting of MoO.sub.3 and WO.sub.

Abstract: A beam splitter formed by laminating a plurality of optical films on a glass substrate having a refractive index of 1.51.+-.0.10. The optical films are first, second, third, fourth, and fifth layers laminated in this order from the glass substrate. The first layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.05-0.15; the second layer has a refractive index of 1.68.+-.0.10 and an optical film thickness of 0.01-0.10; the third layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.50-0.60; the fourth layer has a refractive index of 2.23.+-.0.10 and an optical film thickness of 0.25-0.35; and the fifth layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.25-0.35. The optical film thickness means a relative value represented by n.times.d/.lambda. where n denotes a refractive index; d denotes an actual film thickness, and .lambda. denotes a wavelength deciding the center of a wavelength band.

Abstract: A nonpolarizing beamsplitter is provided, which includes a multilayered stack of alternating layers of a first material and a second material. The first material layers are uniaxially birefringent, and the second material layers are optionally uniaxially birefringent or isotropic. The layers have index of refraction relationships such that for an incident beam having a useful bandwidth, a p-polarized component and an s-polarized component striking the beamsplitter at any angle of incidence .theta. within a desired range, the beamsplitter exhibits substantially the same average reflectivity for the p-polarized component of the incident beam as for the s-polarized component. The invention also includes a method of making a nonpolarizing beamsplitter.

Abstract: A beam splitter formed by laminating a plurality of optical films on a glass substrate having a refractive index of 1.51.+-.0.10. The optical films are first, second, third, fourth, and fifth layers laminated in this order from the glass substrate. The first layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.05-0.15; the second layer has a refractive index of 1.68.+-.0.10 and an optical film thickness of 0.01-0.10; the third layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.50-0.60; the fourth layer has a refractive index of 2.23.+-.0.10 and an optical film thickness of 0.25-0.35; and the fifth layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.25-0.35. The optical film thickness means a relative value represented by n.times.d/.lambda. where n denotes a refractive index; d denotes an actual film thickness, and .lambda. denotes a wavelength deciding the center of a wavelength band.

Abstract: A thin-film color-selective beam splitter and the method of fabricating the same are disclosed. The method includes the steps of: (i) forming a main prism by a pre-selected material, and deciding a first base angle and a second base angle according to the substance and coating characteristics of the pre-selected material; (ii) coating a first multilayer film and a second multilayer film on two slopes of the main prism, in which tilt angles for coating the first multilayer film and the second multilayer film and tilt angles of light entering and emerging the main prism are different, so that spectra of the first multilayer film and the second multilayer film are different, and the first multilayer film can be a red reflective film and the second multilayer film can be a blue reflective film; and (iii) using the pre-selected material to form interface prisms, and adhering the interface prisms to the main prism, so that light can perpendicularly enter and emerge from surfaces of the prism.

Abstract: A beam splitter formed by laminating a plurality of optical films on a glass substrate having a refractive index of 1.51.+-.0.10. The optical films are first, second, third, fourth, and fifth layers laminated in this order from the glass substrate. The first layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.05-0.15; the second layer has a refractive index of 1.68.+-.0.10 and an optical film thickness of 0.01-0.10; the third layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.50-0.60; the fourth layer has a refractive index of 2.23.+-.0.10 and an optical film thickness of 0.25-0.35; and the fifth layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.25-0.35. The optical film thickness means a relative value represented by n.times.d/.lambda. where n denotes a refractive index; d denotes an actual film thickness, and .lambda. denotes a wavelength deciding the center of a wavelength band.

Abstract: A beam splitter formed by laminating a plurality of optical films on a glass substrate having a refractive index of 1.51.+-.0.10. The optical films are first, second, third, fourth, and fifth layers laminated in this order from the glass substrate. The first layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.05-0.15; the second layer has a refractive index of 1.68.+-.0.10 and an optical film thickness of 0.01-0.10; the third layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.50-0.60; the fourth layer has a refractive index of 2.23.+-.0.10 and an optical film thickness of 0.25-0.35; and the fifth layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.25-0.35. The optical film thickness means a relative value represented by n x d/.lambda. where n denotes a refractive index; d denotes an actual film thickness, and .lambda.denotes a wavelength deciding the center of a wavelength band.

Abstract: A multi-color optical display system (10) employs a multi-powered reflective combiner (20) that together with a monochromatic or partly color-corrected relay lens (16) longitudinally corrects a multi-colored image. The combiner typically includes two surfaces (82, 90) of different optical powers with a reflective coating (106, 108) on each of the surfaces. The coatings are chosen to each reflect a specific wavelength range of colored light used in the system and to transmit all other wavelengths. The curvature of each surface is dictated by the aberrations in the color image created by the relay lens. Specifically, each surface is positioned so that its focus (86, 94) coincides with the focal point (58, 60) of the corresponding color component in an intermediate image (18) created by the relay lens so that the final virtual image (22) reflected by the combiner is longitudinally color corrected.

Abstract: An optical coupler divides signal light beam in optical transmission path at predetermined ratio. The optical coupler includes single-layer dividing film evaporated on substrate with optical film thickness being of predetermined value, the film having refractive index which is equal to or smaller than square root of refractive index of substrate, and coupler holder holding single-layer dividing film in optical transmission path to apply signal light beam to single-layer dividing film at incident angle of about 45 degrees. Alternatively, optical coupler includes dividing film made of three films having respective refractive indexes of 1.46.+-.0.10, 1.65.+-.0.10, and 2.30.+-.0.10 and formed in four, five, or seven layers on substrate having refractive index of 1.51.+-.0.10 or 3.50.+-.0.

Abstract: The invention disclosed relates to an interferometer for the far-infrared which provides a high operating efficiency over the spectral range of 50 to 1000 cm.sup.-1. The beamsplitter component comprises a composite of a thin, substantially uniformly thick synthetic resin film having low far-infrared absorption, selected from polyethyleneterephthalate and polypropylene, and a thin substantially uniformly thick coating of germanium. An improved interferometer including a beamsplitter formed of the composite is also disclosed.

Abstract: A double Porro prism having an incident surface, an exit surface, and a plurality of reflecting surfaces for internally reflecting light rays from the incident surface to the exit surface. The plurality of reflecting surfaces having a final reflecting surface that is positioned near the exit surface. The double Porro prism also has a ghost preventing surface that is formed between a ridge of the final reflecting surface and a ridge of the exit surface.

Abstract: A beam splitter formed by laminating a plurality of optical films on a glass substrate having a refractive index of 1.51.+-.0.10. The optical films are first, second, third, fourth, and fifth layers laminated in this order from the glass substrate. The first layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.05-0.15; the second layer has a refractive index of 1.68.+-.0.10 and an optical film thickness of 0.01-0.10; the third layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.50-0.60; the fourth layer has a refractive index of 2.23.+-.0.10 and an optical film thickness of 0.25-0.35; and the fifth layer has a refractive index of 1.44.+-.0.10 and an optical film thickness of 0.25-0.35. The optical film thickness means a relative value represented by n.times.d/.lambda. where n denotes a refractive index; d denotes an actual film thickness, and .lambda. denotes a wavelength deciding the center of a wavelength band.

Abstract: An optical beamsplitter comprises a right angle prism having a hypotenuse and two legs wherein the hypotenuse includes an optically selective coating deposited thereon. An optical element is positioned adjacent the hypotenuse such that the hypotenuse and the optical element form a beamsplitting interface. Various optical elements are utilized to achieve the desired spatial and angular relationships between incoming and outgoing light beams. Several embodiments are disclosed wherein the optical element can comprise a flat plate for providing spatial offset, a wedged plate for producing spatial and angular offset, a lens for adding optical power, or a faceted thin plate.

Abstract: A polarization plane rotator, for executing rotation of the plane of polarization of linearly polarized light that is incident thereon with a predetermined angle of incidence, is formed of a transparent prism or an array of such prisms, each prism having a triangular cross-sectional shape, with first, second and third surfaces having respective lines of intersection that are mutually parallel. The linearly polarized light is incident on the first surface, to be reflected twice in succession at the second and third surfaces, to be emitted from the first surface with the plane of polarization rotated by 90.degree. and the direction of propagation altered. An optical thin film is formed on the second and third surfaces, for substantially reducing an amount of phase difference between the P and S polarization components which results from reflection, thereby ensuring that the emitted light is substantially completely linearly polarized.

Abstract: An optical beamsplitter comprises a right angle prism having a hypotenuse and two legs wherein the hypotenuse includes an optically selective coating deposited thereon. An optical element is positioned adjacent the hypotenuse such that the hypotenuse and the optical element form a beamsplitting interface. Various optical elements are utilized to achieve the desired spatial and angular relationships between incoming and outgoing light beams. Several embodiments are disclosed wherein the optical element can comprise a flat plate for providing spatial offset, a wedged plate for producing spatial and angular offset, a lens for adding optical power, or a faceted thin plate.

Abstract: A dichroic mirror for reflecting a beam of a given color includes a substrate and a multilayered film formed on the substrate. The multilayered film is constituted by a first dichroic reflecting layer, an intermediate layer, and a second dichroic reflecting layer sequentially from the beam incident side. The first dichroic reflecting layer has a smaller reflection range of one of two orthogonal polarized components of the beam than the other of the two orthogonal polarized components. The intermediate layer rotates a polarization plane of at least part of a beam of the one component of the beam passing through the first dichroic reflecting layer, and the second dichroic reflecting layer reflects the at least part of the beam whose polarization plane is rotated by the intermediate layer. A projector having the dichroic mirror is also disclosed.

Abstract: An optical beamsplitter comprises a right angle prism having a hypotenuse and two legs wherein the hypotenuse includes an optically selective coating deposited thereon. An optical element is positioned adjacent the hypotenuse such that the hypotenuse and the optical element form a beamsplitting interface. Various optical elements are utilized to achieve the desired spatial and angular relationships between incoming and outgoing light beams. Several embodiments are disclosed wherein the optical element can comprise a flat plate for providing spatial offset, a wedged plate for producing spatial and angular offset, a lens for adding optical power, or a faceted thin plate.

Abstract: A broad-bandwidth interferometric device is adapted for longitudinal insertion into a cylinder cavity to produce irradiance signals at multiple vertical-scanning positions as a function of optical path differences between a reference mirror incorporated in the probe and the cylinder-wall surface. The light-source beam is passed through an objective lens placed longitudinally in the cylinder and then divided by a beam splitter disposed in fixed relation to the cylinder wall to produce a test beam directed radially to the wall and a reference beam directed axially to a reference mirror disposed in fixed relation to the lens. During scanning, the objective lens and reference mirror are translated together, while the beam splitter remains stationary with respect to the cylinder wall, thereby varying the position of the focal point of the test beam and providing the vertical-scanning effect required to produce interference fringes and a corresponding map of the tested cylinder surface.

Abstract: A broad band polarizing beam splitter includes a first prism, including an incident beam surface, and an interface surface. A second prism is also included with an interface surface. The second prism is positioned adjacent to the first prism with the interface surfaces of the first and second prisms being adjacent to each other. A coating is disposed between the two interface surfaces. The coating is made of a geometric or arithmetic progression of layer thicknesses of alternating high and low refractive indices. A ratio of high refractive index to low refractive index is 1.1 or greater.

Abstract: A beam splitter having an optical multilayer thin film is disclosed. The optical multilayer thin film is formed by laminating six layers in sequence. The laminated six layers comprise: a first layer, a third layer and a fifth layer each having a refractive index from 1.63 to 1.64; a second layer and a sixth layer each having a refractive index from 1.37 to 1.38, a fourth layer having a refractive index from 1.9 to 2.3; in which light is allowed to be incident upon the first layer of the optical multilayer thin film at the angle of incidence equal to or greater than 40.degree.. The reflectances of S and P polarized components of reflected light are substantially equal to each other over a wide wavelength range and substantially no phase difference exists between the S and P polarized components.

Abstract: A polarization separation mirror is made by evaporation-depositing a first multi-layers thin film and a second multi-layers thin film respectively on both surfaces of a transparent substrate, the mirror acts as a polarization beam splitter by cementing it between two transparent prism bodies. By shifting the relative film thicknesses of the first multi-layers thin film and of the second multi-layers thin film, reflecting wavelength range for the S-polarization component is changed.

Abstract: An optical beamsplitter comprises a right angle prism having a hypotenuse and two legs wherein the hypotenuse includes an optically selective coating deposited thereon. An optical element is positioned adjacent the hypotenuse such that the hypotenuse and the optical element form a beamsplitting interface. Various optical elements are utilized to achieve the desired spatial and angular relationships between incoming and outgoing light beams. Several embodiments are disclosed wherein the optical element can comprise a flat plate for providing spatial offset, a wedged plate for producing spatial and angular offset, a lens for adding optical power, or a faceted thin plate.

Abstract: A device for splitting an optical beam into two beams propagating along different optical paths, is provided. The device includes a pair of graded index collimating lenses having their planar collimating ends aligned such that they are both inwardly facing and share a common optical axis. A partially transmitting partially reflective material is disposed between the lenses. At least one of the planar endfaces of the collimating ends are wedge shaped such that a non-zero angle is formed between the two endfaces. This non-zero angle reduces the effect of unwanted optical interference.

Abstract: A mirror coating which possesses properties which are advantageous for the construction of a mirror assembly. The mirror coating has a complex reflective index which is wavelength dependent, and wherein the real component is dominant and the imaginary component is negligible within a predetermined spectral band pass region, and the imaginary component is substantially within a spectral region other than the predetermined spectral band pass region, and wherein the mirror coating exhibits substantially neutral reflected chromaticity as observed with reflected ambient light.

Abstract: A polarizer comprising; a substrate transparent to a light of actual use and optical thin films of a higher refractive index than that of said substrate deposited on both surfaces of said substrate. The substrate is arranged so as to receive the incident light obliquely thereto. When the incident angle and the thickness of the optical thin film are optimally selected, the transmittance for the P polarized light can be made approximately 100%, while that for the S polarized light very small. The polarizer can extract a substantially linearly polarized light from natural light, A projection image display system has the polarizer as its pre-polarizer. The polarizer is also useful for infrared radiation.

Abstract: The present invention is directed to compensation plates for eliminating astigmatism and coma optical aberration in optical systems. In particular, the present invention can be used in LCD projection systems to compensate for aberrations in different color channels. This enables the production of LCD systems completely free of astigmatism and/or coma.

Abstract: This polarization beamsplitter with a substrate-mode holographic structure is used to separate the s-polarization beam with p-polarization, and guide two separated beams at directions parallel to each other. The element consists of a pair of substrate-mode gratings with a specific designed diffraction angle and index modulation on a dielectric substrate. Through the input grating the normally incident beam with one polarization has zero diffraction efficiency and directly pass through the substrate; the beam with another polarization is diffracted at an angle exceeding the critical angle, then propagates through the substrate with total internal reflection to the output grating, and normally coupled out of the element. Thus, the beams with two different polarizations are separated, and two beams propagates at direction parallel to each other.

Abstract: An optical sensor head (400) for providing an optical sensor with a hyperhemispherical field of view is disclosed. The optical sensor head (400) includes first and second lenses (430 and 440), each of the lenses (430 and 440) having a planar surface (434 and 444) and a convex surface (432 and 434). The sensor head (400) further includes a film (420) positioned between the lenses (430 and 440) for splitting the light beams impinging thereon.

Abstract: An optical pickup device capable of maintaining a sufficient amount of laser beam light when recording information on an optical disc and stabilizing the light emission of the semiconductor laser when reproducing information. Each optical component constituting an optical system for an optical pickup device used for both information recording and reproducing is coated with an antireflection film whose spectral reflectance changes in accordance with the wavelength of an incident light. The antireflection film has a high spectral reflectance at a shorter wavelength in the whole range of light emission wavelength covered by the semiconductor laser light source and a low spectral reflectance at a longer wavelength, and is formed on the incident surface or outgoing surface of at least one optical transparent element.

Abstract: A polarization beam splitter which includes a first prism, a second prism, and a dielectric multilayer film which is sandwiched between the first and second prisms is disclosed. The dielectric multilayer film comprising: a plurality of high refractive index layers having a refractive index higher than refractive indices of the first and second prisms; a plurality of intermediate refractive index layers having a refractive index lower than the refractive index of the high refractive index layers; and a plurality of low refractive index layers having a refractive index lower than the refractive index of the intermediate refractive index layers, a reference incident angle .theta..sub.0 of light which is incident on the dielectric multilayer film through the first or second prism being within a range of the following expression:.theta..sub.1 <.theta..sub.0 <.theta..sub.2where ##EQU1## where n.sub.H indicates the refractive index of the high refractive index layers, n.sub.

Abstract: A device is provided for division of a light beam into two sub-beams. A polarization beam splitter is provided having a polarizing layer which, dependent upon polarization direction, resolves an incident polarized light beam into a beam component reflected by the polarizing layer as a first sub-beam, and into a beam component transmitted in a direction of an axis of the light beam. The polarization beam splitter is followed along the beam axis by a phase transformer and by a mirror. The phase transformer undertakes a transformation of a linear polarization into circular polarization upon passage of the transmitted beam component therethrough. The resulting circularly polarized beam component is then reflected at the mirror. The phase transformer then produces phase rotation of the polarization by 90.degree. upon passage of the beam component reflected by the mirror.

Abstract: An optical controlling device has a light transmitting medium showing a low transmittance for specific light wavelength .lambda..sub.1 and a high transmittance for light wavelength .lambda..sub.2 around the light wavelength .lambda..sub.1, and a light emitting device emitting a light of light wavelength .lambda..sub.1 or .lambda..sub.2, and controls light intensity in accordance with changes in a controlled light through light irradiation and light transmission. An optical functional device has a light transmitting medium showing a low transmittance for specific light wavelength .lambda..sub.1 and a high transmittance for light wavelengths .lambda..sub.2 and .lambda..sub.3 around the wavelength .lambda..sub.1 (.lambda..sub.2 <.lambda..sub.1 <.lambda..sub.3), and a light emitting device changing wavelength while accompanying a generation of hysteresis dependent upon the quantity of current injection or light irradiation, and emitting a light having light wavelength .lambda..sub.1, .lambda..sub.2 or .

Abstract: An optical multilayer thin film and a beam splitter having an optical multilayer thin film are disclosed. The optical multilayer thin film is formed by laminating six layers in sequence. The laminated six layers comprise: a first layer, a third layer and a fifth layer each having a refractive index between 1.63 and 1.64; a second layer and a sixth layer each having a refractive index between 1.37 and 1.38, a fourth layer having a refractive index between 1.9 and 2.3; in which light is allowed to be incident upon the first layer of the optical multilayer thin film at the angle of incidence equal to or greater than 40.degree.. In the beam splitter, the reflectances of S and P polarized components of reflected light are substantially equal to each other over a wide wavelength range and substantially no phase difference exists between the S and P polarized components.

Abstract: Arrays of light beams are combined in a manner that minimizes optical power loss by passing a first array of light beams through an angle-variant device onto a target surface while reflecting a second array of light beams off the angle-variant device onto the target surface. The light beams of the first array are arranged to strike the angle-variant device at a first family of angles at which the angle-variant device is substantially transmissive. The light beams of the second array are arranged to strike the angle-variant device at a second family of angles at which the angle-variant device is substantially reflective.