Abstract: A beam blocking and combining optic comprising a wedged optically transparent substrate with a hard dielectric coating applied to a beam combining side of the substrate. The coating has a high reflectance at a laser wavelength and high transmittance at visible wavelengths. The single optical component can combine laser beams into a viewing path and act as a laser safety filter to protect the viewer from reflected laser radiation while providing good colour balance and very low astigmatism in the viewing path and very low astigmatism in the reflected laser beam.

Abstract: An optical imaging system includes optics for imaging a wavefront of electromagnetic radiation to form an image at a detector. The system also includes a plurality of optical phase filters. Each of the phase filters alters phase of the wavefront. The phase filters cooperate to make the system less sensitive to misfocus, as compared to the optical imaging system without the phase filters. Another optical imaging system includes a detector and optics having two or more optical elements for imaging a wavefront onto the detector. The optical elements include aspherical surfaces that cooperate to alter phase of the wavefront such that the optics are less sensitive to defocus as compared to the optics without the aspherical surfaces. The system also includes a post processor for reversing phase alteration induced by the aspherical surfaces to produce an in-focus electronic image.

Abstract: A wavefront correction system using a dual frequency liquid crystal spatial light modulator to vary phase relationships of a wavefront is disclosed. A light beam from the dual frequency liquid crystal spatial light modulator can be split into a reference beam and a plurality of measurement beams to enhance a speed and/or accuracy of phase measurement. A temperature of the dual frequency liquid crystal spatial light modulator can be sensed to facilitate temperature control and/or temperature compensation, so as to enhance the accuracy associated with use of the crossover frequency used to control the dual frequency liquid crystal spatial light modulator.

Abstract: An apparatus for compensating for pixel distortion while reproducing hologram data includes an extraction unit, a determination and calculation unit, a table, and a compensation unit. The extraction unit extracts a reproduced data image from a reproduced image frame including the reproduced data image and borders. The determination and calculation unit determines position values of edges of the extracted reproduced data image, and calculates average magnification error values of pixels within line data from position values of start and end point pixels thereof, which are based on the determined position values of the edges. The table stores misalignment compensation values for the pixels within the line data, wherein the misalignment compensation values correspond to predetermined references for average magnification error values.

Abstract: In optical disc systems, read-out is hampered because of spherical aberrations resulting from cover layer thickness variations or because discs consists of multiple layers. The aberration correcting apparatus (1) of the present invention is arranged to correct such an optical aberration. Therefore, the aberration correcting apparatus (1) comprises a fluid chamber containing a first fluid and a second fluid having different indices of refraction. The first (5) and second fluid (6) are in contact over a meniscus (7) acting as a refractive surface, wherein the shape of the meniscus (7) can be influenced by a magnetic field generated by a magnetizing coil (20).

Abstract: A guide shaft and a guide portion movably guide a lens holder for holding a collimator lens (i.e. correction lens) in an optical axis direction. A stepping motor rotates a screw shaft arranged in parallel to the optical axis direction. A nut member converts a rotating movement of the screw shaft into a rectilinear movement of the optical axis direction. An urging spring urges the lens holder against the guide shaft and the guide portion. The lens holder is driven in the optical axis direction along the guide shaft by the stepping motor, with a first contact portion and a second contact portion of the lens holder being contacted with the guide shaft, and a third contact portion of the lens holder being contacted with the guide portion by an urging force of the urging spring. The optical pickup device having the above arrangement allows for stable driving of a correction lens.

Abstract: A quantum cryptographic key distribution (QKD) endpoint (405) includes a QKD receiver and a feedback system (1600). The QKD receiver receives symbols transmitted over a QKD path. The feedback system (1600) controls a length of the QKD path based on the received symbols.

Abstract: Dichroic beam splitters having non-parallel entry and exit surfaces, reduced distance between such surfaces, and an aspherical exit surface can be advantageously used in dual channel optical systems, particularly when one channel is dedicated to infrared light and the other channel is dedicated to visible or near-infrared light.

Abstract: An extended depth of field is achieved by a computational imaging system that combines a multifocal imaging subsystem for producing a purposefully blurred intermediate image with a digital processing subsystem for producing a recovered image having an extended depth of field. The multifocal imaging system preferably exhibits spherical aberration as the dominant feature of the purposeful blur. A central obscuration of the multifocal imaging subsystem renders point-spread functions of object points more uniform over a range of object distances. An iterative digital deconvolution algorithm for converting the intermediate image into the recovered image contains a metric parameter that speeds convergence, avoids stagnations, and enhances image quality.

Abstract: An exemplary optical hybrid includes a 50/50 un-polarized beam splitter, a folding prism, a beam shifter, a spacer and a phase shifter such that from an input S-beam (signal) and an L-beam (reference), four outputs, S+L, S?L, S+jL, S?jL, are produced. The phase difference of S and L at the four output ports is phi_0, phi_0+90-degrees, phi_0+180-degree, phi_0+270-degree, where the phase difference between S and L at the S+L port is an arbitrary number phi_0 and the phase difference between S and L at the other output ports, S?L, S+jL, S?jL, is 90, 180 and 270, respectively, shifted from phi_0.

Abstract: A common-aperture optical system includes a reflective telescope having a common boresight, an entrance pupil, an exit pupil, and a beam path extending from the entrance pupil to and beyond the exit pupil. A beam splitter intersects the beam path so that the beam path is incident upon the beam splitter. A light sensor is positioned to receive an input light beam traveling along the beam path after the beam path intersects the beam splitter and passes the exit pupil of the reflective telescope. A light source produces an output light beam incident upon the beam splitter and positioned to inject the output light beam into an inverse of the beam path and toward the entrance pupil of the reflective telescope. A diverger corrects at least one of the input light beam and the output light beam.

Abstract: A high-performance image-forming optical system made compact and thin by folding an optical path using reflecting surfaces arranged to minimize the number of reflections. The image-forming optical system has a single prism. When image-side three surfaces of the prism are defined as a surface A, a surface B and a surface C in order from the image plane side thereof, at least one of the surfaces B and C has a rotationally asymmetric curved surface configuration that gives a power to a light beam and corrects aberrations due to decentration. The optical system leads light rays from an object to the image plane without forming an image in the prism and has a pupil in the prism. The surface A is a transmitting surface through which rays exit from the prism. The surfaces B and C are internally reflecting surfaces, which are positioned to face each other to form a Z-shaped optical path.

Abstract: A lens arrangement is presented. The lens arrangement comprises a first element having a concave reflective surface and defining an optical axis of the lens arrangement, and a second substantially flat and at least partially reflective element spaced-apart from the first element along the optical axis. The second element is configured to allow light passage therethrough and is oriented with respect to the optical axis and the first element such that at a predetermined angle of incidence of an input light beam onto the second element, the input light beam is reflected onto the reflective surface of the first element and reflected therefrom to pass through the second element.

Abstract: A polarizing beam splitter that includes at least one prism, and a reflective polarizing film. The prism comprises a first polymeric material, and has at least one curved outer surface and an incident surface, where the reflective polarizing film is disposed adjacent the incident surface.

Abstract: A high-performance image-forming optical objective lens made compact and thin, particularly in the object side direction, by twice folding the optical path by means of two prism lenses longitudinally separated and arranged in an angular relationship to one another. The prisms have entrance and exit faces each of which is constructed of a curved surface having optical power, as well as having a rotationally symmetric polynomial aspheric attribute. The image-forming optical objective is particularly suited to helmet-mounted applications wherein the angular means for folding the optical path provides for an optical objective configuration that closely conforms to the exterior surface contour of the helmet, while providing a minimal forward projection in object space from the helmet.

Abstract: An interferometer includes a beamsplitter, and a compensator. At least one surface of the beamsplitter or compensator has a non-zero power. In one embodiment, one surface of the beamsplitter is flat and the other surface of the beamsplitter is curved. In another embodiment, the interferometer includes a beamsplitter and a compensator, each having at least one surface of non-zero power, and the non-zero power of the beamsplitter and the non-zero power of the compensator are equal to each other.

Abstract: A wavefront correction system using a dual frequency liquid crystal spatial light modulator to vary phase relationships of a wavefront is disclosed. A light beam from the dual frequency liquid crystal spatial light modulator can be split into a reference beam and a plurality of measurement beams to enhance a speed and/or accuracy of phase measurement. A temperature of the dual frequency liquid crystal spatial light modulator can be sensed to facilitate temperature control and/or temperature compensation, so as to enhance the accuracy associated with use of the crossover frequency used to control the dual frequency liquid crystal spatial light modulator.

Abstract: The disclosure relates to Method and Apparatus for Super Montage Large area Spectroscopic Imaging. In one embodiment of the disclosure, a method for producing a spectroscopic image of an object includes the steps of (a) irradiating the object with light to thereby produce from the object scattered and/or emitted light for each of a plurality of wavelengths; (b) producing separately for each of the plurality of wavelengths a plurality of substantially contiguous sub-images of the object; (c) compensating for spatial aberrations in ones of the sub-images for a select one of the plurality of wavelengths; (d) compensating for intensity aberrations between ones of the substantially contiguous sub-images for one of the plurality of wavelengths; and (e) combining the sub-images for the select one wavelength to thereby produce said spectroscopic image of the object.

Abstract: A pulse compressor. In one embodiment, the pulse compressor comprises an optical medium adapted for receiving a beam of light in an incident optical path and dispersing it into its constituent spectral colors to form a dispersed beam of light in an output optical path, where the optical medium is configured such that when an incident beam of light is received by the optical medium, it passes through the optical medium four times, in a back and forth manner, and leaves the optical medium in the form of a corresponding output beam of light.

Abstract: A method for optimizing cost and performance in a lens assembly is disclosed. The method relaxes the constraints of optically correcting lateral chromatic aberration and distortion on the lens assembly and instead electronically corrects for lateral chromatic aberration and distortion. As a result the lens assembly transmissivity and MTF improve dramatically and other aberrations are reduced as a result of re-optimizing the lens assembly merit function. The cost and volume of the lens assembly are reduced as well. The optimized lens assembly could be used in rear or front projection display devices as a well as image acquisition devices.

Abstract: A system, method and software product to optimize optical and/or digital system designs. An optical model of the optical system design is generated. A digital model of the digital system design is generated. Simulated output of the optical and digital models is analyzed to produce a score. The score is processed to determine whether the simulated output achieves one or more goals. One or more properties of at least one of the optical model and the digital model is modified if the goals are not achieved. The analyzing, processing and modifying is repeated until the goals are achieved, and an optimized optical system design and optimized digital system design are generated from the optical and digital models.

Abstract: An optical device includes an elongated tube configured for insertion into a body and optical members located in the tube. The optical members are configured to have an optical invariant-to-clear aperture semidiameter ratio greater than about 0.05 and an optical path difference less than about a value of the optical invariant divided by at least 250 times a midrange wavelength in a spectral range from about 435.8 nm to about 656.3 nm, and are preferably formed of an extraordinary dispersion optical material. A method includes conducting polychromatic light through at least one optical member located in an elongated tube configured for insertion into a body, where the optical members have an optical invariant-to-clear aperture semidiameter ratio greater than about 0.05 and an optical path difference less than about a value of an optical invariant divided by at least 250 times the midrange wavelength from about 435.8 to about 656.3 nm.

Abstract: A wavefront correction system using a dual frequency liquid crystal spatial light modulator to vary phase relationships of a wavefront is disclosed. A light beam from the dual frequency liquid crystal spatial light modulator can be split into a reference beam and a plurality of measurement beams to enhance a speed and/or accuracy of phase measurement. A temperature of the dual frequency liquid crystal spatial light modulator can be sensed to facilitate temperature control and/or temperature compensation, so as to enhance the accuracy associated with use of the crossover frequency used to control the dual frequency liquid crystal spatial light modulator.

Abstract: An optical module 1 comprises a first optical element F1, a first light receiving subassembly PD1, a second optical element F2, a second light receiving subassembly PD2, a light emitting subassembly LD3 for generating light, and a light transmitting part 3 optically coupled to the first optical element. The light emitting subassembly LD3, the first optical element F1, the second optical element F2 and the first light receiving subassembly PD1 are arranged along a predetermined plane S1. The light emitting subassembly LD3, the first optical element F1, the second optical element F2, and the second light receiving subassembly PD2 are arranged along another predetermined plane S2. The predetermined plane S1 intersects at a predetermined angle with the other predetermined plane S2.

Abstract: A complex objective lens composed of a hologram and an objective lens, capable of realizing stable and high-precision compatible reproducing/recording of a BD with a base thickness of about 0.1 mm for a blue light beam (wavelength ?1) and a DVD with a base thickness of about 0.6 mm for a red light beam (wavelength ?2). In an inner circumferential portion of the hologram, a grating is formed, which has a cross-sectional shape including as one period a step of heights in the order of 0 time, twice, once, and three times a unit level difference that gives a difference in optical path of about one wavelength with respect to a blue light beam, from an outer peripheral side to an optical axis side. The hologram transmits a blue light beam as 0th-order diffracted light without diffracting it, and disperses a red light beam passing through an inner circumferential portion as +1st-order diffracted light and allows it to be condensed by an objective lens.

Abstract: An aberration correction apparatus comprising a liquid crystal device which includes a first electrode layer that is formed with regions divided concentrically, a second electrode layer that is formed with regions divided concentrically, and a liquid crystal that is sandwiched in between the first electrode layer and the second electrode layer, and which transmits an incident light beam therethrough, an objective lens which condenses the light beam transmitted through the liquid crystal device, and a liquid-crystal-device drive circuit which drives the liquid crystal device, wherein the liquid-crystal-device drive circuit impresses a potential which belongs to a predetermined region included in a liquid crystal characteristic that is a relationship between potentials impressed on the respective electrode layers sandwiching in the liquid crystal therebetween and a phase change magnitude of the light beam transmitted through the liquid crystal, on the concentric regions formed in the first electrode layer, and

Abstract: A high-performance image-forming optical system made compact and thin by folding an optical path using reflecting surfaces arranged to minimize the number of reflections. The image-forming optical system has a single prism. When image-side three surfaces of the prism are defined as a surface A, a surface B and a surface C in order from the image plane side thereof, at least one of the surfaces B and C has a rotationally asymmetric curved surface configuration that gives a power to a light beam and corrects aberrations due to decentration. The optical system leads light rays from an object to the image plane without forming an image in the prism and has a pupil in the prism. The surface A is a transmitting surface through which rays exit from the prism. The surfaces B and C are internally reflecting surfaces, which are positioned to face each other to form a Z-shaped optical path.

Abstract: A multiple-axis imaging system having optical elements whose optimal image positions can be individually adjusted, comprising a plurality of optical array elements having respective optical axes and being individually disposed with respect to one another to image respective sections of an object; and a plurality of image position shifting devices corresponding to respective optical elements for separately establishing the image positions for a plurality of the optical array elements. The multi-axis imaging system preferably comprises a miniaturized microscope array. The shifting devices may comprise wavelength filters or optical-path-length-altering elements, such as a plane parallel plates. The devices may also comprise a pair of wedges that adjustably overlap one another, the wedges having apexes that point in opposite directions and respective corresponding planar surfaces that are parallel to one another.

Abstract: A polarizing beam splitter is disclosed that includes a first prism, a second prism, and a reflective polarizing film disposed between the first prism and the second prism. The first prism comprises a first polymeric material, and has a first outer curved surface and an additional outer surface. The second prism comprises a second polymeric material, which in some embodiments may be the same as the first polymeric material, and has a second outer curved surface.

Abstract: A display device for displaying information is provided with an optical system for guiding the light of the display device to the eye, the optical system having, in the order in the proceeding direction of the light, an entrance face for receiving the light, a curved face for totally reflecting the light and a reflecting face concave to the eye side and adapted to reflect the light toward the eye. The reflected light is transmitted by the curved face and reaches the eye. Thus there is obtained a compact display device with satisfactorily suppressed aberrations.

Abstract: An optical head device may include a laser light source, an objective lens for converging a laser beam emitted from the laser light source on an optical recording medium, a parallel planar half mirror which is disposed on an optical path directing from the laser light source to the optical recording medium and which partially transmits the laser beam emitted from the laser light source diagonally as a divergent beam, and an aberration correcting element for correcting aberration which is occurred when the laser beam before converged on the optical recording medium is transmitted through the half mirror. Since the aberration correcting element is disposed on an optical path directing from the laser light source to the optical recording medium, a satisfactory spot can be formed on an optical recording medium.

Abstract: A display device using a light modulator and having an improved numerical aperture (NA) of an after-edge lens system is disclosed. The display device includes an illumination lens, a diffractive light modulator, an NA improvement unit, a filter system and a projection system. The illumination lens converts light into linear parallel light, and outputs the linear parallel light. The diffractive light modulator produces diffracted light beams having a plurality of diffraction orders by modulating the linear parallel light incident from the illumination lens according to an external control signal. The NA improvement unit causes + and ? diffracted light beams of the diffracted light beams to come close to each other. The filter system passes only some of the diffracted light beams having predetermined orders, therethrough. The projection system focuses the diffracted light beams onto an object and allows the focused diffracted light to scan the object.

Abstract: Laser-scanning microscope with at least one detection radiation input, in which an aperture plate is installed in front of the detector, whereby optics with variable transmission lengths and a fixed focal distance is provided for focusing varying wavelengths of the detected light onto the aperture plate level at the detection radiation path, which realizes the imaging from the infinite space into an image level with a finite conjugate distance, and/or with at least one light source launched via an optical fiber, whereby collimator optics with a fixed focal distance, and a variable conjugate distance are down-streamed from the fiber output, which transfers the point source at the fiber output with a numerical aperture into a parallel beam in the infinite space in front of the scan-objective lens, whereby a wavelength-dependent, at least partial compensation of the chromatic distortion of the micro-objective lenses occurs by means of turning the chromatic curve for the illumination wavelength used.

Abstract: A lens system for use in a two-stage projection system that relays light output from a first imager on a pixel-by-pixel basis onto a second imager (e.g. an LCOS). The lens system includes a double gauss lens set having a distortion of less than about 0.015% with at least about 90% of the light energy of a specific pixel projected within about a 15.4 micrometer square. Thus a projection system that enhances the contrast ratio for video images, particularly in the dark state, and reduces contouring artifacts, can be achieved.

Abstract: A system and method for correcting optical aberrations in optical devices, such as wide-field microscopes, optical tweezers and optical media devices, such as DVD drives. The system uses adaptive optics to correct optical aberrations, such as spherical and space-variant aberrations. Spherical aberrations can be corrected using one adaptive optical elements and space-variant aberrations can be corrected using numerous adaptive optical elements in tandem. The adaptive optical elements may be of several types, such as a liquid lenses, deformable membrane mirrors or various liquid crystal phase and amplitude modulators. Adaptive optics can also be used to simultaneously shift the focus of the optical device and correct optical aberrations.

Abstract: A personal monitoring system to be worn by an individual in a hazardous situation comprises an enclosed face mask which includes a transparent shield over at least the eves a sensor module secured to the individual which includes a plurality of sensors, a microprocessor and an RF transmission means operable to transmit data obtained by the sensors. The face mask includes a heads-up display comprising a housing containing an electroluminescent display panel, an optical lens, a microprocessor, and an RF receiver operable to receive data from the sensor module. The housing is configured to allow the mounting of the display panel and optical lens in a spaced-apart arrangement so that the display panel is viewed through the lens. The system of the invention also includes a central Incident Commander Module comprising an RF transceiver and a display panel which can receive and display sensor data from a plurality of head-worn devices.

Abstract: Methods and apparatus for reducing noise in optical apparatus comprising a delay line by utilizing a plurality of wavelength specific delay lines to delay an input waveform such as a pulse rather than a single delay line. In a preferred embodiment an apparatus is configured to generate an optical waveform by distributing an input optical waveform among a plurality of environmentally isolated legs, wherein each leg contributes to the generated optical waveform by reflecting back at least a portion of light distributed to the leg, and the distribution among the plurality of legs is at least partially wavelength dependent.

Abstract: An optical device comprises a dichroic beamsplitter for splitting an object beam into a reflected beam having a first waveband and a transmitted beam having a second waveband; an astigmatism-correcting lens element, disposed in the optical path of the transmitted beam; and a coma-correcting lens element, disposed in the optical path of the transmitted beam.

Abstract: Apparatus for imaging an area of a surface along a viewing angle that is oblique to the surface includes an afocal optical relay, which is adapted to form a tilted initial image of the area by collecting optical radiation from the area along an optical axis oriented at the viewing angle. A tilt correction unit is coupled to correct a tilt of the initial image so as to form a substantially undistorted intermediate image. A magnification module is coupled to focus the intermediate image onto an image detector.

Abstract: A lens arrangement is presented. The lens arrangement comprises a first element having a concave reflective surface and defining an optical axis of the lens arrangement, and a second substantially flat and at least partially reflective element spaced-apart from the first element along the optical axis. The second element is configured to allow light passage therethrough and is oriented with respect to the optical axis and the first element such that at a predetermined angle of incidence of an input light beam onto the second element, the input light beam is reflected onto the reflective surface of the first element and reflected therefrom to pass through the second element.

Abstract: The lifetime of optical components used in deep-UV (DUV) excimer laser systems, including systems in a MOPA configuration, can be increased by reducing the intensity of pulses incident upon these components. In one approach, an output pulse can be “stretched” in order to reduce the peak power of the pulse. A pulse stretching component can be used, which can be mounted outside the laser enclosure with a horizontal beam path in order to provide a delay line with a minimum impact on the laser system footprint. The horizontal beam path also can minimize the number of optical components in the arm containing the high power beam. A beamsplitting prism can be used with the delay line to avoid the rapid degradation of coatings otherwise exposed to intense UV beams. The prism can expand the beam in the delay line in order to minimize beam intensity and losses due to reflection.

Abstract: An optical pickup module with enhanced aberration correctability is disclosed. This pickup includes more than two different types of laser light sources, an objective lens for collecting and focusing any one of the laser beams leaving the light sources onto an optical disc, and an aberration correction device of the liquid crystal (LC) type, which is disposed between the light sources and the objective lens. The aberration corrector has a surface on which multiple spaced-apart electrodes are patterned for enabling aberration correction relative to incident beams. The corrector controls the potential of a voltage being applied to each electrode in deference to incident beam properties and variations occurrable thereto, e.g., wavelength, effective beam diameter and relative incidence position offsets, thereby to optimally correct beam aberrations, such as coma aberration or wavefront aberration. An optical information reproduction apparatus using the pickup is also disclosed.

Abstract: The present invention provides a projection image display technology capable of correcting astigmatism due to use of a polarized-beam splitter, thus ensuring high-resolution projection images. A wire-grid polarized-beam splitter (or the like) of a flat-plate-like structure is used as a polarized-beam splitter, and an astigmatism correction element, such as a cylindrical lens, is provided between the polarized-beam splitter and a projection lens unit.

Abstract: Laser beams respectively emitted from a SHG blue laser unit and a red semiconductor laser unit that have photo detectors respectively are turned into parallel lights by a collimator lens and then coupled by a dielectric multi-layer film mirror so as to be propagated on the same optical axis. The dielectric multi-layer film mirror is configured so as to transmit light with a wavelength of 500 nm or shorter and reflect light with a wavelength of 500 nm or longer for both P wave and S wave. The lights that are transmitted and reflected by the dielectric multi-layer film mirror pass through a polarizing hologram and a phase variable wave plate and are focused on an optical disk by an objective lens. In this manner, a simple configuration can realize a compatibility with many types of optical disks and a stable signal detection even when using a polarizing optical detection system.

Abstract: An optical system with mechanical adjustment provides for the rotation and/or translation of one or more optical phase filters to variably select an extended depth of field, aberration-tolerance, and/or anti-aliasing properties of an optical imaging system. By adjusting the amount of phase induced on the wavefront, a user may select image quality selectively. The system may further automatically counter change of focus and/or aperture to maintain substantially constant image properties. Typically, two phase filters are used and moved concurrently to achieve desired image properties.

Abstract: A projection apparatus including a light source which generates light beams, an optical projection system which projects the light beams generated by the light source onto a screen, and a reflection device which is positioned between the light source and the optical projection system. The reflection device includes a plurality of mirrors capable of reflecting incident beams generated by the light source to travel toward the optical projection system. The projection apparatus also includes an optical illumination system which is positioned in an optical path between the light source and the reflection device and is tilted or decentered with respect to the optical axis of the light source to allow light beams generated by the light source to enter the reflection device at a predetermined angle.

Abstract: A terrestrial telescope with digital camera has an imaging optical system having a group of objective lenses and an imaging element disposed at a position at which an optical image is formed by the group of objective lenses. An observation optical system is provided for observing the optical image transmitted by the group of objective lenses. An optical element is inserted into the optical axis so as to be retractable from the optical axis during imaging. The optical element has a transmission surface having a single-eccentric toroidal configuration with different curvatures in vertical and horizontal planes of the optical element for correcting the position on the imaging element at which the optical image is formed so that the position on the imaging element at which the optical image is formed remains substantially unchanged regardless of whether the optical element is inserted into or retracted from the optical axis of the group of objective lenses.

Abstract: An optical system and method comprising acquiring radiation in a plurality of spectral bands, each acquired by a discrete collector, receiving the acquired radiation in one or more of the spectral bands with one or more afocal zoom optics, each receiving radiation from a different collector, and aligning each point of fields of view of the collectors to a fraction of a pixel.

Abstract: A decentering optical system which takes a substantially parallel beam as input light, includes a prism having a medium whose refractive index is greater than 1, and four optical surfaces disposed at boundary surfaces of the medium so as to be mutually decentering or to slant. The four optical surfaces form a light-incident surface through which the input light enters, at least two internal-reflective surfaces which reflect internally the input light entering inside, a splitting surface which splits an optical path of the input light reflected by any one of these internal-reflective surfaces, into a transmission optical path and a reflection optical path; and a transmitting surface which emits the input light traveling along the reflection optical path towards an exterior. Real images are formed along each of the transmission optical path and the reflection optical path.

Abstract: Light (22) is projected from an image projector (20), in response to an image information signal (18) and is controllably refracted in response to a first control signal (26), for projecting refracted light (27) onto a screen (28). The screened light is for providing viewable images of varying size occupying all or part of the screen. The viewable images are refracted in response to a second control signal (64) for viewing the images of increasingly smaller size with correspondingly increasing magnification.