Abstract: The object of the invention relates to a method for scanning with an optical beam (50) using a first acousto-optic deflector (15, 15?) having an optical axis along a Z-axis and at least one acousto-optic crystal layer (14), involving directing the optical beam (50) in the first acousto-optic deflector (15, 15?), and deflecting the optical beam (50) along an X-axis perpendicular to the Z-axis by means of the first acousto-optic deflector (15, 15), during which generating a plurality of acoustic chirp signals (30) in the at least one acousto-optic crystal layer (14) of the acousto-optic deflector (15, 15?) by—generating a first acoustic chirp signal (30a) having a duration of ? in the acousto-optic crystal layer (14), then—generating a second acoustic chirp signal (30b) in the acousto-optic crystal layer (14) within a ? period of time counted from the start of the generation of the first acoustic chirp signal (30a).

Abstract: A method for driving an acousto-optic element with an acousto-optic crystal and a piezoelectric transducer for setting the acousto-optic crystal in mechanical vibration includes driving the piezoelectric transducer with a drive signal with at least one drive frequency. The at least one drive frequency in alternation takes on a plurality of different values around a center frequency during a passage of a mechanical vibrational wave through the acousto-optic crystal, such that a grating that is produced owing to density fluctuations in the acousto-optic crystal exhibits different grating spacings at the same time.

Abstract: A frequency spectrum detection system including: a frequency-scan light source, a phase modulator, an optical filter, an optical fiber, a photodetector, a power divider, an electric amplifier, a combiner, an electric filter, and an oscilloscope. The frequency-scan light source, the phase modulator, the optical filter, the photodetector, and the electric amplifier form a ring-shaped optoelectronic oscillator resonant cavity, which is configured to generate a frequency-scan signal. The combiner is configured to receive a signal to be measured. The phase modulator is configured to modulate the combined electrical signal onto a frequency-scan optical signal. The optical filter is configured to selectively attenuate or amplify one sideband of double sidebands of the double-sideband phase-modulated optical signal. The photodetector is configured to detect a signal filtered by the optical filter.

Abstract: The light control device includes a light modulation module and a dispersion compensation module. The light modulation module is used for modulating an incident light field to obtain a target diffraction light field. The dispersion compensation module is used for performing dispersion compensation on the target diffraction light field, so that light fields having different wavelength in the target diffraction light field have the same spatial location distribution, or the light fields having different wavelength in the target diffraction light field have the same spatial angle distribution.

Abstract: A head mounted display apparatus and an eye-tracking apparatus thereof are provided. The eye-tracking apparatus includes a first wave guide apparatus, a voltage control beam splitter, a first beam splitter, and an image capture apparatus. The voltage control beam splitter provides a first light path between the image capture apparatus, the voltage control beam splitter, and a target zone according to a control signal during a first time period. The voltage control beam splitter provides a second light path between the image capture apparatus, the first wave guide apparatus, the first beam splitter, and the target zone according to the control signal during a second time period. The image capture apparatus respectively captures a first image and a second image of the target zone through the first light path and the second light path.

Abstract: The invention relates to a method for scanning along a continuous scanning trajectory with a scanner system (100) comprising a first pair of acousto-optic deflectors (10) for deflecting a focal spot of an electromagnetic beam generated by a consecutive lens system (200) defining an optical axis (z) in an x-z plane, and a second pair of acousto-optic deflectors (20) for deflecting the focal spot in a y-z plane being substantially perpendicular to the x-z plane, characterized by changing the acoustic frequency sweeps with time continuously in the deflectors (12, 12?) of the first pair of deflectors (10) and in the deflectors (22, 22?) of the second pair of deflectors (20) so as to cause the focal spot to move continuously along the scanning trajectory.

Abstract: An apparatus (10) for structured illumination microscopy (SIM) comprises a pulsed femtosecond MiTai laser (11) operable to generate a pulsed beam. The beam pulses are directed on to a specimen (12) via an optical arrangement including a beam steering apparatus comprising a pair of acousto-optic deflectors AODx, AODy, each operable to vary the deflection angle of the beam in response to variation in the frequency of an applied acoustic deflection signal, and an acousto-optic modulator AOM. The frequency of the acoustic deflection signals applied to the AODs and/or the frequency of the acoustic compensation signal applied to the AOM in the present invention is dynamically modulated. This dynamic modulation can increase the effective AODxy scan angle in each direction by about 4 mrads (equivalent to a 15% increase in the area of the field of view). Furthermore, dynamic modulation of the compensation frequency also improves the evenness of the illumination over the field of view.

Abstract: The invention relates to an acousto-optic deflector comprising a bulk of acousto-optic medium and acoustic wave generator coupled to the bulk, characterized by that the acoustic wave generator comprises at least two different electro-acoustic transducers for generating acoustic waves in the bulk.

Abstract: The invention relates to a compensator system adapted to compensate for the angular dispersion of electromagnetic beams deflected by at least one acousto-optic deflector of an optical system, wherein the angular dispersion of each deflected beam is dependent on the deflection angle obtained by the deflecting acoustic frequency of the acousto-optic deflector, characterized in that the compensator system comprises: —a first lens group for spatially separating the deflected beams of different deflection angle and angular dispersion by focusing the beams substantially into the focal plane, —a compensator element having a first surface and a second surface, and being arranged such that the first surface of the compensator element lies substantially in the focal plane of the first lens group, and the first and second surfaces of the compensator element have nominal radiuses R1 and R2 that together work as prisms with tilt angles ? and prism opening angles ?p that vary with the distance from the optical axis so as t

Abstract: Methods and apparatus for optimising, improving or maximising the efficiency of an acousto-optic lens (AOL) system are disclosed. Data relating to efficiency is used to select drive frequencies of the acousto-optic devices (AODs) forming the AOL, thereby both increasing the usable field of view and reducing a prior art patternation problem. Preferably according to the invention, drive frequencies are selected that maximise efficiency of transmission through the AOL. When scanning, the centre of each scan is optimised to be of maximum efficiency.

Abstract: A microscope, comprising a stage onto which is placed an item, a lens having a tunable acoustic gradient index of refraction (TAG lens) sufficiently proximate to said stage to magnify an image of the item, a viewing point for providing for viewing of the magnified image, and a pulsed illuminator capable of illuminating the stage and synchronously pulsed with an operating frequency of the TAG lens.

Abstract: The invention relates to a method for scanning along a continuous scanning trajectory with a scanner system (100) comprising a first pair of acousto-optic deflectors (10) for deflecting a focal spot of an electromagnetic beam generated by a consecutive lens system (200) defining an optical axis (z) in an x-z plane, and a second pair of acousto-optic deflectors (20) for deflecting the focal spot in a y-z plane being substantially perpendicular to the x-z plane, characterised by changing the acoustic frequency sweeps with time continuously in the deflectors (12, 12?) of the first pair of deflectors (10) and in the deflectors (22, 22?) of the second pair of deflectors (20) so as to cause the focal spot to move continuously along the scanning trajectory.

Abstract: The invention relates to an external cavity tunable laser. The laser comprises an extracavity collimating lens arranged outside a laser cavity, and a laser output mirror, a laser gain medium, an intracavity collimating lens, an active optical phase modulator and a tunable optical filter all arranged sequentially inside the laser cavity. The laser further comprises an active polarization rotator arranged behind the tunable optical filter, a polarization beam splitter arranged behind the active polarization rotator, a first etalon and a first total reflection mirror arranged in the direction vertical to the optic axis of a laser cavity output lens, a second etalon and a second total reflection mirror arranged in the direction of the optic axis of the laser cavity output lens, and a laser drive and control circuit.

Abstract: An illumination device for illuminating a target to be combated includes a laser light source for emitting light along a beam path, a first modulator in the beam path and configured to manipulate a direction of the beam path in a first plane, a phase plate in the beam path having a variety of different optical thicknesses, and a control device connected to the light source and the first modulator and is configured to activate the first modulator using different frequencies, so that the beam path is deflected over a control period of time up to a first angle.

Abstract: Methods, systems and apparatus for manipulating electromagnetic radiation such as laser beams. A method and apparatus for correcting magnification chromatic aberration utilises one or more dispersive lenses such that long wavelength components are magnified less than short wavelength components. A telecentric relay is preferred to achieve this aim. Further, the use of polarisers to block the undesired zeroth order components of diffraction emanating from acousto-optic deflectors (AODs) is disclosed. Furthermore, specific designs of AOD including narrow transducer AODs which produce a diverging acoustic wave and AODs having two transducers and a selection switch are disclosed.

Abstract: An acousto-optic (AO) device includes an AO interaction crystal for receiving and propagating a light ray along an optical propagation direction (OPD). A piezoelectric transducer is on at least one surface of the AO interaction crystal for receiving an electrical signal and emitting an acoustic wave into the AO interaction crystal. An electrode is on the piezoelectric transducer for coupling the electrical signal to the piezoelectric transducer. The electrode is a patterned electrode that includes a plurality of different transverse edge positions. The plurality of different transverse edge positions span a position range of at least five percent of an average height (Havg) of the electrode.

Abstract: Methods, systems and apparatus for manipulating electromagnetic radiation such as laser beams. A method and apparatus for correcting magnification chromatic aberration utilizes one or more dispersive lenses such that long wavelength components are magnified less than short wavelength components. A telecentric relay is preferred to achieve this aim. Further, the use of polarizers to block the undesired zeroth order components of diffraction emanating from acousto-optic deflectors (AODs) is disclosed. Furthermore, specific designs of AOD including narrow transducer AODs which produce a diverging acoustic wave and AODs having two transducers and a selection switch are disclosed.

Abstract: The invention is directed to an acousto-optic lens (AOL) and corresponding method. The AOL of the invention comprises a first and second acousto-optic deflector, each being arranged to support a respective acoustic wave. The AOL includes a driver for synthesizing first and second drive signals for the respective first and second acousto-optic deflectors. The driver is arranged to synthesize the drive signals so as to be phase-modulated by functions that can be expressed as a Taylor series having one or more coefficients greater than second order. The functions are preferably non-sinusoidal and have sufficient magnitude at the higher orders to effect one or more of fixed aberration correction, dynamic aberration correction and Z-scanning.

Abstract: Methods, systems and apparatus for manipulating electromagnetic radiation such as laser beams. A method and apparatus for correcting magnification chromatic aberration utilises one or more dispersive lenses such that long wavelength components are magnified less than short wavelength components. A telecentric relay is preferred to achieve this aim. Further, the use of polarisers to block the undesired zeroth order components of diffraction emanating from acousto-optic deflectors (AODs) is disclosed. Furthermore, specific designs of AOD including narrow transducer AODs which produce a diverging acoustic wave and AODs having two transducers and a selection switch are disclosed.

Abstract: An acousto-optic device includes an acousto-optic medium having a multi-layer nanostructure; and a sonic wave generator configured to apply sonic waves to the acousto-optic medium having the multi-layer nanostructure. The acousto-optic medium having the multi-layer nanostructure includes a second layer formed of at least two materials that have different dielectric constants and alternate with each other; and a first layer disposed on a first surface of the second layer and formed of a first material, and/or a third layer disposed on a second surface of the second layer and formed of a fourth material.

Abstract: An acoustically-focused optical lens is provided that uses acoustic transducers arranged in diametrically-opposed pairs around an exterior surface of a cylindrical tube in order to concentrate (heavier-than-water metallic) particles suspended in water within the interior of the tube to be along a central axis of the tube. The transducers are activated in accordance with higher order (and odd order) Bessel functions to create an asymmetric mode in order to create the central axis node. Distortions in the optical lens can be further reduced by arranging two or more of the tubes in series with their central axes aligned.

Abstract: Methods, systems and apparatus for manipulating electromagnetic radiation such as laser beams. A method and apparatus for correcting magnification chromatic aberration utilizes one or more dispersive lenses such that long wavelength components are magnified less than short wavelength components. A telecentric relay is preferred to achieve this aim. Further, the use of polarizers to block the undesired zeroth order components of diffraction emanating from acousto-optic deflectors (AODs) is disclosed. Furthermore, specific designs of AOD including narrow transducer AODs which produce a diverging acoustic wave and AODs having two transducers and a selection switch are disclosed.

Abstract: An acousto-optic module is provided, including a number of partially coupled optical resonators distributed within a dielectric medium and at least one acoustic transducer mounted on a surface of the dielectric medium for injecting an acoustic wave into the optical resonators so as to diffract light passing therethrough by means of Bragg diffraction. This acousto-optic module has been applied in particular to an improved tuneable optical filter in which an acoustic shear wave is generated and which travels through the acousto-optic module in a direction substantially parallel with a polarized light signal passing therethrough. The acousto-optic module is also applied to an improved optical frequency shifter.

Abstract: Methods, systems and apparatus for manipulating electromagnetic radiation such as laser beams. A method and apparatus for correcting magnification chromatic aberration utilises one or more dispersive lenses such that long wavelength components are magnified less than short wavelength components. A telecentric relay is preferred to achieve this aim. Further, the use of polarisers to block the undesired zeroth order components of diffraction emanating from acousto-optic deflectors (AODs) is disclosed. Furthermore, specific designs of AOD including narrow transducer AODs which produce a diverging acoustic wave and AODs having two transducers and a selection switch are disclosed.

Abstract: In one embodiment, a sub-pixel rendering method includes receiving 3D image data associated with pixel intensity values of N two-dimensional images having multiple sets of corresponding pixels. Each set of corresponding pixels includes N pixels (one pixel from each of N images) and each pixel has a green sub-pixel, a red sub-pixel and a blue sub-pixel. The method further includes mapping, for each selected set, N green sub-pixels, N red sub-pixels and N blue sub-pixels to M sub-pixels on a display to form a stereogram of the scene. The above mapping includes mapping N green sub-pixels from N images to N green sub-pixels on the display, mapping N red sub-pixels from N images to L red sub-pixels on the display, and mapping N blue sub-pixels from N images to K blue sub-pixels on the display, where L does not exceed N and K is lower than N.

Abstract: An electrooptical device comprises an electrooptical layer between electrodes. The electrooptical layer includes a dispersion medium and particles contained in the dispersion medium. The particles are colored a first color, while the dispersion medium is colored a second color. The first and second colors are related to each other based on a relationship of complementary colors.

Abstract: Detecting a pulse of a signal includes receiving the signal and a light beam. The signal drives a spatial light modulator to modulate the light beam, where the complex amplitude of the modulated light beam is proportional to the signal current. The modulated light beam passes through an optical system and is detected by an optical detector array. A processor identifies a portion of the signal comprising the pulse.

Abstract: An optical tunable laser design (100) for the optic telecommunication industry is disclosed in this invention. This new design is economical, reliable, robust and with superior optical performances. The design offers broadband tunability, high output power, narrow laser line-width and high SMSR. And in addition, the tunable laser is distinguishable from conventional designs by the mere facts that there are no moving parts, therefore, making it very reliable, and the tuning method of this invention is non-thermal and non-mechanical making its tuning very fast in the sub-millisecond range. In the manufacturing front, it is low cost and easy to produce. It can be achieved with automation equipment like those used in the IC placement and PC assembly industry, therefore, the products as that disclosed in this invention can be provided with significantly reduced production costs and marketed with very competitive price.

Abstract: Digital control of frequency and/or amplitude modulation techniques of an intracavity and/or extracavity AOM (60) facilitate substantially full extinction of a laser beam (90) to prevent unwanted laser energy from impinging a workpiece (80); facilitate laser pulse amplitude stability through closed-loop control of pulse-to-pulse laser energy; facilitate beam-positioning control including, but not limited to, closed-loop control for applications such as alignment error correction, beam walk rectification, or tertiary positioning; and facilitate employment of more than one transducer on an AOM (60) to perform any of the above-listed applications.

Abstract: An optical tunable laser design for the optical telecommunication industry is disclosed in this invention. This new design is economical, reliable, robust and with superior optical performances. The design offers broadband tunability, high output power, narrow laser line-width and high SMSR. And in addition, the tunable laser is distinguishable from conventional designs by the mere facts that there are no moving parts, therefore, making it very reliable, and the tuning method of this invention is non-thermal and non-mechanical making its tuning very fast in the sub-millisecond range. In the manufacturing front, it is low cost and easy to produce. It can be achieved with automation equipment like those used in the IC placement and PC assembly industry, therefore, the products as that disclosed in this invention can be provided with significantly reduced production costs and marketed with very competitive price.

Abstract: An acousto-micro-optic deflector (AMOD) is provided. This device uses a special combination of an acousto-optic deflector (AOD) and a micro-optic deflector (MOD) to provide agile gimballess beam steering over large angles. The combination is driven such that the entire field of regard of the device is accessible, and continuous contact with the target point is maintained.

Abstract: A system, method and article of manufacture is disclosed that provides an improved, more efficient, laser beam modulator and splitter. The combined device includes a crystal with a horizontal cross-sectional shape of a pentagon. The crystal includes a top surface, a bottom surface, and a first through fifth sides. The first side and the second side are substantially parallel. An absorber is mounted on the third side. The fourth and fifth sides are substantially opposite to the third side. The fourth and fifth sides form an angle substantially equal to 180 degrees minus the sum of a first a second Bragg angles. The crystal also includes at least one layer. For one embodiment, each layer includes an incident window on the first side, an active window on the second side and a transparent axis between the incident window and the active window. A first and a second transducer are mounted on the fourth and fifth sides.

Abstract: An acousto-optic scanning system, which relies on two counter propagating acoustic waves with the same frequency modulation. This scheme completely suppresses the linear frequency chirp, and thus enables the generation of fast non-linear scans and non-constant linear scans. By changing the phase between the modulating signals, this scheme also provides fast longitudinal scans of the focal point.

Abstract: A display apparatus includes a laser light source for emitting a light beam having a coherence length; a beam expander for expanding the light beam; a spatial light modulator; beam shaping optics for shaping the expanded laser beam to provide uniform illumination of the spatial light modulator, the beam shaping optics including a fly's eye integrator having an array of lenslets; a diffuser located in the light beam between the laser light source and the beam shaping optics; an electrically controllable de-speckling modulator for modifying the temporal and spatial phase of the light beam; and a projection lens for producing an image of the spatial light modulator on a distant screen.

Abstract: The invention relates to an optical modulation device for coupling an entering radiation field (12), with which an incident radiation field (40) is divided into a transmitted branch (40T) and a diffracted branch (40B) by means of a first acousto-optical modulation and a diffracted and a transmitted branch are respectively generated by means of a second acousto-optical modulation so that the transmitted branch (40BUT) resulting from the deflected diffracted branch (40BU) and the diffracted branch (40TUB) resulting from the deflected transmitted branch (40TU) propagate in approximately the same direction and form a first radiation field (46) as a result of essentially constructive interference and, in addition, the transmitted branch (40TUT) resulting from the deflected transmitted branch (40TU) and the diffracted branch (40BUB) resulting from the deflected diffracted branch (40BU) propagate in the same direction and form a second radiation field (48) as a result of essentially destructive interference.

Abstract: A three channel acousto-optic modulator may be used to implement a projection display or a scanner. Each of three channels are deflected differently by the modulator. The channels may correspond to the primary color planes.

Abstract: A 3-channel modulation system for a high power laser and a modulation method for a high power laser are disclosed herein. In a preferred implementation, the modulation system includes a laser light source, a light modulator modulating the light generated from the laser light source and including a pair of electrodes having a predetermined area disposed on one side of the light modulator, an image signal generating sub-system, a drive circuit sub-system for operating the electrodes so that the image signal being generated from the image signal generating sub-system is provided through the electrodes to the light modulator, a first cylindrical lens positioned between the laser light source and the light modulator so that the area and form of the light generated from the laser light source are modified and the modified light enters the light modulator, and a second cylindrical lens positioned at an output side of the light modulator to modify the area and form of the light modulated by the light modulator.

Abstract: A laser beam intensity modulation system has a variable delay circuit that is used to control the relative delay in the delivery of a video signal between two cascaded AOM's. This delay circuit is controlled by a delay controller that monitors the intensity modulation of the laser beam to provide feedback control. This system maximizes the rise and fall times of the beam to generate precise beam modulation required for high speed image setters.

Abstract: A multi-beam emitting device which splits a light beam emitted from a light source into a plurality of beams with a beam splitter to emit a plurality of beams. As the beam splitter, an optical waveguide type acoustooptic element or the like is used. A multi-beam emitting device according to the present invention has a beam splitter which drives an acoustooptic element with a plurality of electric signals with different frequencies applied thereto so as to deflect a light beam emitted from a light source and split the light beam into a plurality of beams, a signal generator which generates the electric signals with different frequencies which are used for the drive of the acoustooptic element, a modulating circuit which turns on and off the electric signals generated by the signal generater individually based on a data signal, an intensity control circuit which controls the light source to change the intensity of the light beam emitted therefrom.

Abstract: A folded acoustic traveling wave lens arrangement imparts multiple passes of an incident optical beam through the traveling wave lens, and thereby effectively maximize utilization of acoustic power. A lens of optically transmissive bulk material, such as quartz, is disposed in the path of an incident light beam which is spatially scanned by a light beam deflector. The bulk material of the lens element has a reflective layer disposed upon at least one of its surfaces, and is configured such that an incident light beam undergoes multiple passes through the acoustic wavefront propagating through the lens, prior to emerging from the lens. Aberration in the emerging beam due to multiple passes through the bulk material is corrected by a pupil plane correction plate.

Abstract: An inventive array of thin film actuated mirrors is provided with an active matrix having an array of switching devices, an array of actuating structures and an array of mirrors, wherein each of the actuating structures is cantilevered on the active matrix, and each of the switching devices is positioned on the active matrix beside the position at which each of the actuating structures is cantilevered. In the array, during the operation of the array, since each of the mirrors is connected to the actuating structure through a recessed portion thereof, the mirror stays planar, allowing more accurate and effective reflection of the light beams, which will, in turn, enhance the overall optical efficiency of the array.

Abstract: A method and device for shaping both the temporal and spatial profiles of an input optical pulse to generate an output optical waveform are described. The method includes the step of dispersing the spectral frequencies of the input pulse. These frequencies are then focused with a cylindrical lens to form a two-dimensional optical field. The field is imaged on a mask featuring a two-dimensional array of pixels. The amplitudes, phases, or phases and amplitudes of the two-dimensional optical field are then filtered with the mask. The filtered spectral frequencies are then recombined to form the collective temporal profile of the output waveform. The two-dimensional optical field is then imaged in a sample plane to form the spatially coherent regions.

Abstract: Optical systems are disclosed which are capable of generating and rapidly changing time delays of electrical signals for true time delay beam formation and beam steering and for signal processing applications. The systems utilize an interferometer configuration. A first optical modulator in a first leg of the interferometer is used to modulate coherent light with the signal to be delayed. In a second leg of the interferometer, a second optical modulator provides beam steering to a prism stack, which produces a set of plane reference waves having a range of orientations required to generate a desired range of time delays. Preferably the optical modulators are acousto optic Bragg cells. Alternatively, a stack of lens pairs or diffractive optical elements or a holographic optic element may be used in place of the prism stack. The modulated optical signal from the first leg interferes on an array of photodiodes with the reference waves from the second leg.

Abstract: An optical system of an optical neural network model for parallel data processing is disclosed. Taking advantage of the fact that an auto-correlation matrix is symmetric with respect to a main diagonal and the weights for modulating the values of diagonals of the auto-correlation matrix are equal to each other, the configuration of an optical modulation unit is simplified by a one-dimensional modulation array on the one hand, and both positive and negative weights are capable of being computed at the same time on the other hand. In particular, the optical system makes up a second-order neural network exhibiting invariant characteristics against the translation and scale.

Abstract: Optical systems are disclosed which are capable of generating and rapidly changing time delays of electrical signals for true time delay beam formation and beam steering and for signal processing applications. The systems utilize an interferometer configuration. A first optical modulator in a first leg of the interferometer is used to modulate coherent light with the signal to be delayed. In a second leg of the interferometer, a second optical modulator provides beam steering to a prism stack, which produces a set of plane reference waves having a range of orientations required to generate a desired range of time delays. Preferably the optical modulators are acousto optic Bragg cells. Alternatively, a stack of lens pairs or diffractive optical elements or a holographic optic element may be used in place of the prism stack. The modulated optical signal from the first leg interferes on an array of photodiodes with the reference waves from the second leg.

Abstract: A plurality of fiber optic laser members are supported in an apertured plate so as to form an array supplied by an optical pump. Individual members may have the light passing there through modulated by respective modulators. Light from the fiber optic laser array illuminates an optical storage medium which stores information. The resulting output undergoes Fourier transformation and optical filtering. Filtered light then undergoes inverse Fourier transformation and detection.

Abstract: Optical systems are disclosed which are capable of generating and rapidly changing time delays of electrical signals for true time delay beam formation and beam steering. The systems utilize an interferometer configuration. A first optical modulator and a Fourier transform lens define a Fourier transform plane in a first leg of the interferometer. In a second leg of the interferometer, a second optical modulator provides beam steering to a prism stack, which produces a set of plane reference waves having a range of orientations required to generate a desired range of time delays. Preferably the optical modulators are acousto optic Bragg cells. Alternatively, a holographic optic element could be used in place of the prism stack.

Abstract: A high resolution two-directional optical scanner, comprising a source of very high frequency light pulses, a first acousto-optic cell for diffracting the light pulses towards an image plane so as to form on a predetermined area thereof a line of pixels corresponding to the data, and a second acousto-optic cell intermediate the first acousto-optic cell and the image plane for intercepting the light pulses diffracted by the first acousto-optic cell and diffracting them towards the image plane in a second direction perpendicular to the line of pixels at an angle dependent on a scanning signal fed to the second acousto-optic cell. The invention is particularly suited for use with flat bed plotters and reduces the need to transport the plotter bed mechanically in order to achieve scanning normal to the direction of each complete scan line.

Abstract: An adaptive filter having a correlation weighting structue having a single Bragg cell, acting as a tapped delay line and having an input and an output, the Bragg cell intensity modulating a write laser beam for computing correlation values, and modulating a read laser field strength for multiplying the correlation values by delayed signal values. A photorefractive element is arranged such that substantial portions of diffracted and undiffracted light components from the single Bragg cell overlap within the photorefractive element. A write laser is intensity modulated by an error signal to produce an optical write signal that is received at the photorefractive element input and which writes correlation coefficients in the photorefractive element. A read laser produces a light signal, a portion of which is diffracted by the single Bragg cell, the portion of the light signal that is not diffracted by the single Bragg cell being partially diffracted by the photorefractive element.

Abstract: A multi-channel/multi-layer optical gate contained within a fiber-optic housing having any number of optical cells disposed within the housing. The optical cells are made up of non-linear organic polymers surrounded by a piezoelectric crystal, which is in turn connected to a photovoltaic device. When the photovoltaic device is activated, the piezoelectric crystals cause the non-linear organic polymers to change their refractive index, causing an interruption of a reference laser beam. An output detector is disposed within the fiber-optic housing for detecting the reference laser beam.