Abstract: An object of the invention is to provide a polarization scrambler wherein the polarization of linearly polarized signal light can be rotated to facilitate obtaining a minimum degree of polarization, and wherein scrambling operation is possible even if signal light of optional polarization states is input. Accordingly with the polarization scrambler, a polarization rotation section is provided on an input side on a chip on which is formed an optical waveguide, and a polarization scrambling section is provided on an output side. With the polarization rotation section, the polarization of linearly polarized signal light which is transmitted by the optical waveguide is rotated by means of an acousto-optic effect due to an elastic surface wave generated by an electrode, so as to become 45.degree. with respect to a vertical direction of the optical waveguide.

Abstract: An acoustic traveling wave lens structure for an acousto-optic scanner comprises a confined height fluid-containing channel, upon which a scanned optical beam to be modulated by a acoustic traveling wave is incident. The channel is bounded by spaced-apart walls that extend between a first end of the scanner channel, to which an acoustic transducer is coupled, and a second end of the channel that terminates an acoustic traveling wave launched from the acoustic transducer. The thickness of the channel is linearly tapered from the first end to the second end, so as to maintain a constant acoustic power density. To compensate for the attenuation in acoustic power through the water medium, the waveguide may be heated, to maintain the temperature of the liquid medium (water) within the waveguide channel within a prescribed temperature range over which the acoustic velocity remains substantially constant or undergoes a relatively small variation.

Abstract: A stress-optic beam scanner and system which includes a stress-optic material selected to permit the scanning of an optical beam on a target typically over a scanning angle of greater than five degrees. The system includes a piezoelectric element controlled by a microprocessor to control the mechanical stress applied to the stress-optic material.

Abstract: A polarization independent acousto-optic tunable filter (PIAOTF) used for multiwavelength switching and routing in wavelength division multiplexing (WDM) networks. In the PIAOTF an incident unpolarized light beam is divided to propagate and to be diffracted along two polarization division branches. By using polarization converters and equal optical paths for the two polarization division channels, a PIAOTF is created which minimizes polarization dependent loss and polarization mode dispersion. Furthermore, a preferred embodiment of the AOTF using an elongated acousto-optic interaction medium is described that provides the additional advantages of narrow bandwidth, lower drive power and easier alignment.

Abstract: In a non-collinear type acousto-optic tunable filter, a source light beam is made off-perpendicularly incident on a crystal body, so that the cross section of the source light beam is narrowed within the crystal body. As a result, the receiving angular aperture becomes large to increase the amount of light collected into the crystal body. Consequently, highly accurate spectrometry can be performed even if the intensity of the source light beam is low. Further, the non-diffraction part of the crystal body can be eliminated by the off-perpendicular incidence of the source light beam, so that the sufficient diffraction length of acoustic and optic waves can be obtained.

Abstract: There are proposed light beam scanning method and device for scanning with plural light beams split by using a multi-frequency acousto-optic device (AOM). By remarkably increasing the number of light beams, an image is recorded at a higher speed. Plural incident light beams are split in the subsidiary scanning direction by different multi-frequency acousto-optic devices. The split light beams are displaced so as not to overlap one another in the subsidiary scanning direction, while respective sets of light beams split by the acousto-optic devices are deviated in a main scanning direction, for scanning. The deviation in the main scanning direction is compensated with a clock timing of an image signal. The light beams split by the AOMs may be alternately positioned in the subsidiary scanning direction. Alternatively, a set of light beams split by one AOM may be adjacent to a set of light beams split by another AOM in the subsidiary scanning direction.

Abstract: A laser system is described which concurrently directs highly equivalent diffracted beams derived from an initial laser beam to both sides of a substrate. The diffracted beams may be generated with sufficient energy to soften spots on the surfaces of the substrate to form texture bumps as are used on substrates for magnetic disks. The diffracted beams are generated by a multichannel acousto-optic modulator (MCAOM) having at least two channels. The crystal in the MCAOM has at least two mounting faces oriented so that the acoustic transducers mounted thereon generate acoustic fields which intersect the incident laser beam at a common angle, i.e., the Bragg angle. Energizing any of the transducers causes a corresponding first order beam to be diffracted out.

Abstract: An electro-acoustic transducer is attached to a block of optical material, and forms an acoustic standing wave in the block; the acoustic standing wave periodically changes the refractive index of the optical material, and forms high refractive index portions alternated with low refractive index portions; and the high refractive index portions serve as optical wave guides, and the electro-acoustic transducer easily produces the optical wave guide in the block.

Abstract: An acousto-optic tunable filter and filtering method are disclosed providing for a significantly increased number of available wavelength channels for output. The filter combines a diffraction grating, the grating vector of which is transverse to light propagation direction, with an acousto-optic beam deflector, which, by accommodating a narrow spectral bandwidth (about 5% that of conventional acousto-optic tunable filters), provides significantly increased output bandwidth and available wavelength channels (by a factor of approximately 20).

Abstract: A channel counter that can count the number of given wavelength channels in a specific wavelength range in a simplified system. A channel counter comprises an acousto-optic deflector, an optical fiber for transmitting light to the acousto-optic deflector, an optical receiver for receiving light transmitted from the optical fiber and diffracted by the acousto-optic deflector, an oscillator for driving the acousto-optic deflector, a scanning circuit for time-scanning the oscillation frequency of the oscillator, and a count circuit for counting the number of peaks of an electric signal output from the optical receiver per scanning duration of the scanning circuit.

Abstract: A multi-channel acousto-optic spatial modulator for fast signal processing by a plurality of acousto-optic modulating cells connected in a line. The multi-channel acousto-optic spatial modulator in accordance with the present invention comprises a plurality of modulating cells each for modulating the incident light, acoustic waves being created within each of said plurality of modulating cells; and a plurality of absorbing plates each interposed between said two modulating cells for shielding the acoustic wave created within one of said two modulating cells from being propagated into the other of said two modulating cells.

Abstract: In order to increase the available signal processing bandwidth of an acousto-optic coherent channelizer, the optical beam spot-shaping and projection components of the channelizer are configured to project M reference beam spots upon each photodetector of the channelizer's photodetector array. The parameters of the reference Bragg cell, reference signal R(t), and Fourier optics components are such that they project M reference beam spots upon each photodetector of the channelizer's photodetector array, where M is the desired system bandwidth multiplication factor. No change to the configuration of the photodetector array or its associated post-detection signal processing electronics is required.

Abstract: This invention relates to an acousto-optic time-integrating correlator for rocessing broadband Doppler-shifted signals. The present invention uses a conical lens telescope to compensate, in one dimension, for the differences in the absolute values of Doppler shift occurring in broadband signals. A laser light beam is expanded to a sheet beam using a conventional beam expander. The sheet beam is split and redirected using a modified Koster's prism. The two sheet beams are them directed toward a SAW device. The SAW device contains two tilted transducers. The inputs to the SAW device are counterpropagating A Doppler-shifted sheet beam and an undiffracted sheet beam are processed by respective conical lens telescopes. The outputs of the conical lens telescopes are combined with associated unprocessed sheet beams and combined by respective modified Koster's prisms and imaged onto respective two-dimensional photodetectors. The output of one photodetector is subtracted from the other to reduce offsets.

Abstract: A multi-beam scanning system for scanning a curved imaging surface includes at least one radiation emitter which emits first and second beams of radiation. A spin deflector, rotatable about a spin axis, directs the first beam to form a first scan line and the second beam to form a second scan line on the imaging surface. A deflection element, disposed in the path of the first beam and upstream of the spin deflector, operates to deflect the first beam with respect to the rotation of the spin deflector. The spin deflector is impinged by beams of radiation only at a distance, other than zero, from the spin axis.

Abstract: An xyz coordinate system is determined so that a z-axis may coincide with an incident direction of an incident light, an x-axis may coincide with a polarizing direction of the incident light and a y-axis may be defined as the right-handed system from the z-axis and x-axis. An acousto-optic element is rotated around the z-axis, around the axis in a direction of propagation of an ultrasonic wave and around an axis B perpendicular to a plane formed by the z-axis and the direction of propagation of the ultrasonic wave, so that the attitude of the acousto-optic element to the incident light is adjusted.

Abstract: An acousto-optic modulator having an ultrasonic medium for controlling light from a light source by diffracting the light and a transducer portion having electrodes for generating an acoustic wave in the ultrasonic medium, wherein the transducer portion includes two transducers each having an electrode. The AOM is provided with two electrodes by using two transducers, thereby facilitating impedance matching with a driver. The two transducers may be installed so that their polarization directions are opposite to each other, thereby obtaining maximum power transfer to the ultrasonic medium.

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: An optical switch is formed by: at least one switch driving circuit for generating ultrasonic waves; at least one electric acousto-optic element forming at least one diffraction grating therein upon being applied with the ultrasonic waves generated by the switch driving circuit; at least one polarization rotator for rotating a polarization plane of a first primary diffracted light produced by the diffraction grating, by 90.degree.

Abstract: A laser radar (LADAR) including an acoustic-optical (AO) laser scanner for deflecting a pulsed laser beam through a plurality of angles, means for diffracting the deflected laser beam from the acoustic-optical laser scanner into a plurality of laser beams and a linear detector array including a plurality of detector elements respectively positioned to receive reflected energy from the respective plurality of laser beams such that a line scan is produced composed of a plurality of pixels.

Abstract: A photo-acoustic leak detection system for detecting a gas leaking from a component includes a beam, having a wavelength, incident on the component and producing an acoustic signal. A second acoustic signal is also produced when an air source dilutes the gas leaking from the component. A signal processor receives sensor signals indicative of both acoustic signals and uses the second sensor signal as a non-leak baseline measurement and provides an output signal indicative of whether a leak exists.

Abstract: An object surface height measuring device with two acousto-optical modules for refracting light from a light emitter with predetermined refractive indices depending on frequency modulation so that the light is swept over the X and Y axes of an object, and two other acousto-optical modules synchronized with the signals of the first two acousto-optical modules, respectively, so that the light reflected from the object is focused onto a light receiving portion. The change in the height of the object is measured from the variation between the spot of light focused onto the light receiving portion and the center of the light receiver.

Abstract: An ultra-wideband signal processor, such as that employed for processing narrow time domain radar return pulses, includes a coherent acousto-optic Bragg cell channelizer having a plurality of IF outputs from which a plurality of IF output signals respectively representative of energy content of respectively different frequency portions of the RF input signal are derived. A summing circuit is coupled to sum the IF output signals to produce a summation signal representative of their average energy content. This average energy signal is compared with a threshold to determine if the input signal is a valid RF signal. A delay circuit delays a selected one of the IF output channels by a time sufficient to accommodate summation of the channelizer outputs and determining whether a valid RF signal is present. A digital signal processor processes the delayed selected output signal in response to the summation signal exceeding the threshold.

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: A multi-beam scanning system for scanning a curved imaging surface includes at least one radiation emitter configured to emit a first beam of radiation and a second beam of radiation. A spin deflector, rotatable about a spin axis, directs the first beam to form a first scan line and the second beam to form a second scan line on the imaging surface. At least one acousto-optic element, disposed in the path of at least one of the beams and upstream of the spin deflector, is operable to deflect the at least one beam with respect to the spin axis of the spin deflector.

Abstract: A technique of stabilizing the output of an acoustooptic modulator. A laser passes a light beam through the acoustooptic modulator. A driver circuit connects to a drive electrode of the acoustooptic modulator. RF generators deliver drive power at a first carrier frequency and compensation power at second and third carrier frequencies, one higher and the other lower than the first carrier frequency. The driver circuit modulates the drive power and the compensation power such that compensating acoustic energy induced in the acoustooptic modulator complements drive acoustic energy, and the spatial content of the drive acoustic energy. The combined drive power and the complementing compensating power maintain the spatial thermal energy distribution inside the acoustooptic modulator substantially constant. Consequently, beam steering and thermal ellipticity are stabilized and remain substantially constant throughout the operating range of the modulator.

Abstract: An active recognition system comprises a transceiver, tracking electronics, an optical processor, and a data handler. The transceiver transmits chirped pulses and receives a series of reflected ?replicas of the chirped pulse! replica pulses from ?features of! an object ?of interest!. The tracking electronics controls the transceiver to determine object range for gating the optical processor. The optical processor includes a "signal" Bragg cell driven by the reflection signal so that ?a! throughgoing light ?beam! is angularly redistributed as a function of the local spatial frequency of the acoustic waveform within the modulation aperture of the signal Bragg cell. At a first focal plane, the light defines a one-dimensional light distribution that includes moving spots that correspond to respective reflection replicas.

Abstract: A system for electronically powering an acoustooptic device. A radio-frequency (RF) generator supplies RF drive power at a drive carrier frequency. A signal source delivers a modulating signal. An RF modulator modulates the RF drive power with the modulating signal. Two compensating RF power generators supply high-frequency and low-frequency compensating power at frequencies greater than and less than the drive carrier frequency. Operational amplifiers and modulators modulate the compensating power with signals derived from the signal source such that the modulated compensating power is the complement of the modulated RF drive power. A summer combines the modulated RF drive power and compensating power to drive the acoustooptic device such that the spatial thermal energy distribution inside the acoustooptic device remains substantially constant.

Abstract: An acousto-optic deflector device having a piezoelectric thin film and IDT formed on a substrate for deflecting a light by causing an SAW generated at an SAW generator region to interact with the light at a light waveguide region. The piezoelectric thin film is constructed of a first piezoelectric thin film having a relatively high resistance and a high piezoelectricity in the SAW generator region, and a second piezoelectric thin film having a smaller light propagation loss than the first piezoelectric thin film 3a in the light waveguide region.

Abstract: An apparatus for, and method of, decreasing a temporal duration of an optical input pulse having an input power spectrum associated therewith, the apparatus and method operative on at least unchirped optical input pulses. The apparatus comprises: (1) a zero-dispersion pulse shaper for receiving the optical input pulse and spectrally spreading the input pulse to produce a spectrally-spread pulse and (2) a modulator array interposed within the zero-dispersion pulse shaper for receiving the spectrally-spread pulse and selectively attenuating a portion of the power spectrum of the spectrally-spread pulse by a predetermined amount to produce a selectively-attenuated spectrally-spread pulse, the zero-dispersion pulse shaper focusing and recombining the selectively-attenuated spectrally-spread pulse to produce an output pulse having a broader power spectrum than the input pulse, the output pulse further having a temporal duration less than the input pulse, regardless of whether the input pulse is chirped.

Abstract: A high definition image projector is provided for modulating light using an acousto-optic tunable filter according to image signals and projecting the modulated light on a screen. An image is obtained by modulating a light beam by pixel units according to the image to be displayed and directly projecting the modulated light beam on the screen in corresponding pixel units. High quality images can thus be displayed on a large screen. By adopting a high-output light source, a high luminance image can be obtained.

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: An acoustooptic device includes a Y-cut and Z-propagation LiNbO.sub.3 substrate or 128.degree.-rotating Y-plane LiNbO.sub.3 substrate, an optical waveguide layer which is formed on at least a part of the LiNbO.sub.3 substrate and has a higher light refractive index than the LiNbO.sub.3 substrate, an interdigital electrode which is formed on the LiNbO.sub.3 substrate and generates Rayleigh waves, and a dielectric thin film layer formed on the interdigital electrode.

Abstract: An apparatus for both deflecting a beam of light illuminating a spot on a surface and varying the size of the spot, electronically, without changing any system components. The apparatus includes an acousto-optic deflector driven with a linear FM signal produced by a chirp signal generator. The linear FM signal is characterized with a dispersion rate, and the chirp signal generator includes a chirp dispersion selector to vary the dispersion rate. A beam of collimated light passes through the acousto-optic deflector and appropriate focusing optics image the beam onto a spot in a nominal focal plane. The chirp dispersion selector sets the dispersion rate in accord to a nominal rate, resulting in the beam illuminating a spot in the focal plane. Generally, the focal plane coincides with a wafer surface, of the type having periodic and non-periodic features on it. The spot size may be varied from that of a diffraction limited spot to a spot whose maximum size is system dependent.

Abstract: An acousto-optic modulator utilizing light diffraction by phased acoustic waves in a birefringent crystal. The wavevector of the resultant acoustic wave is selected so that the tangents to the loci of the wavevectors of the incident and diffracted light are parallel. This provides a large acceptance angle for the acousto-optic modulator. By simultaneously choosing the acoustic wavevector to be tangential to the locus of the diffracted light wavevector, the acousto-optic modulator also achieves increased modulation bandwidth.

Abstract: A phase conjugation mirror including a non-linear medium (1) and a focusing lens (2), in which a beam to be reflected (F1) is displaced relative to a non-linear medium. The displacement is obtained through displacement of the focusing lens and has application in the stabilization of the reflectivity of a phase conjugation mirror.

Abstract: An optical beam scanning apparatus which includes: an optical modulator which emits an optical beam in a direction corresponding to the frequency of an inputted signal; scanning device for scanning the optical beam; a scanning lens; a storage device which stores data for correcting the displacement of the optical beam passing through the scanning lens caused by an aberration of the scanning lens for each scanning position of the optical beam; and a device which, based on the data stored in the storage device, alters the frequency of the signal to be inputted to the optical modulator for each scanning position of the optical beam so as to correct the displacement of the optical beam caused by the aberration of the scanning lens.

Abstract: Acousto-optical devices utilize crystals of a novel material thallium arsenic sulfide (Tl.sub.3 AsS.sub.3) grown from a melt. A Tl.sub.3 AsS.sub.3 crystal is cut and parallel faces are prepared and polished. A piezoelectric transducer connected to an RF generator is placed on the acoustic face to generate sound waves. The light is directed through the optical face of the crystal and interacts with the acoustic waves. These devices may be used in signal processing, spectrum analyzing, spectroscopic, liquid analyzing and spectral imaging systems.

Abstract: The invention relates to an optical switch (1) which is switchable by means of light. The switch (1) comprises an optical wave-guiding structure (3) having an entrance (5) to which a signal can be applied and an exit (7). The refractive index of the wave-guiding structure (30) is variable by means of light intensity. The switch (1) further comprises a radiation source unit (15) whose radiation can be injected into the wave-guiding structure (3). The radiation source unit (15) comprises a pulsed laser (17) having a repetition time T and a pulse duration p and a medium (19) for transporting the radiation supplied by the laser (17). The radiation source unit (15) is provided with setting means (21 ) for stabilizing the wavelength of the laser (17) at a number n of selected wavelength bands from a number N of possibly selectable wavelength bands within one and the same pulse supplied by the laser (17). Moreover, the medium (19) is dispersive at a wavelength-dependent travel time t.sub.

Abstract: An optical communications system which facilitates rapid establishment of communications between two stations (1, 2). The system uses acousto-optic cells (5, 6) for scanning and frequency modulating a laser beam. The frequency shift introduced by the cell (6) is indicative of the direction of arrival of the beam at a remote station (2). By detecting the shift, the relative positions of the two stations (1,2) may be deduced. The invention is suitable for use with secure communication systems and IFF systems.

Abstract: A laser scanner is disclosed, in which M, the lateral magnification obtained from the first and the second optical members, V.sub.1, the scanning velocity of the scanning beam on the beam receiving surface and V.sub.s, the velocity of the acoustic wave inside the acoustic beam modulator are substantially related by M=-V.sub.1 /V.sub.

Abstract: The present invention is a scanning system and a novel method for compensating for the variations in the output power of the beam from an A-O cell. The novel method involves varying the amount of drive current through the laser diode in such a fashion as to compensate for the loss of power due to diffraction inefficiencies. The amount of driving current is dependent upon the amount of power desired in the output beam from the A-O cell. The system and method of the present invention sets the output power from the A-O cell to a desired value. As the diffraction efficiency increases at other portions of the scan, the drive current is cut appropriately to compensate for the increased efficiency; thus keeping the output spot power at the desired value. Likewise, as the diffraction efficiency decreases at other portions of the scan, the drive current should be increased to compensate for the decrease in efficiency; thereby maintaining the desired value.

Abstract: An apparatus and method for optical telecommunication includes introducing a laser beam emitted from a light source at a first station into an optical fiber, providing an ultrasonic wave obtained by modulating a voice signal by a signal-applying-device at a work section to the optical fiber, modulating a polarized light passing through the optical fiber in amplitude and frequency, receiving the polarized light with the shifted wave plane at a light-receiving section in a second station, detecting at the light-receiving section in the second station the polarized light which has been modulated by the signal-applying device in the work section, and demodulating the polarized light to obtain a voice signal.

Abstract: Light from a laser (10) is divided by a beam splitter (12) to provide signal (15) and reference (14) channels. The signal channel light is expanded (11) to illuminate an acousto-optic (AO) device (13). This leads to a spatial distribution of Doppler shifted frequencies. This spatial distribution then illuminates a spatial light modulator (SLM) (19) such that a number of parallel and discrete optical channels (112) emerge. In a local area network (LAN) the optical signal channels are coupled into a single mode optical fibre (22) and then heterodont to the reference laser light from a further optical fibre (23) in an optical coupler (25). In a receiver the modulated light is detected (32) and the detected signal connected to the transducer of an AO device (35). The AO device (35) is illuminated by a receiver laser light (36) and the emerging modulated light is incident on a focal plane detector array (39) where each detector (310) then receives light corresponding to each of the transmitted channels (311).

Abstract: Devices for deflecting an optical beam under the action of an ultrasonic beam propagating in a block of active acousto-optical material and operating under Bragg tangential conditions, with the acousto-optical interaction being anisotropic. The devices also include entry and exit faces into this material blocks which are inclined at angles .alpha. and .beta. such that the incoming beam and the emerging beam after the interaction are significantly parallel, keeping operation under Bragg tangential conditions. The devices can also be used to make a spectrum analyzer with a very large number of points and very high dynamics.

Abstract: A scanning laser microscope capable of detecting a fine structure producing low contrast and easily measuring the length, the volume, and so forth of an object. A laser beam is focused onto the object. The beam is scanned at regular intervals, or in a digital fashion, in two dimensions. Light scattered from the object is detected by a detector to observe an image of the object. The output signal from the detector is digitized into a given number of gray levels in synchronism with the digital scans. The object image can be stored in a memory and processed while correlating the scanned position with the intensity of the scattered light at this position.

Abstract: An improved, multicolored video imaging system to provide a video image on a projection surface, which system includes a red, blue and green pulsed laser as a light source to provide inlet beams, an acoustic-optical cell to receive the inlet beams, an electrical signal to a sound transducer on the cell to provide a sound-modulated outlet beam; a projection surface to display the multicolored image and a projection system to project the outlet beam onto the projection surface to display the video image. The system includes as an improvement a solid state actuator to move a distance in a 45.degree. direction to backtrack the line of image of the outlet beam and a ramp signal device to provide a ramp signal that is proportional in time to the pulse duration of the input beams when the pulse duration is longer than the pixel propagation time for a line of image to be displayed, thereby minimizing the blurring of the line of image displayed.

Abstract: A heterojunction acoustic charge transport device (HACT) having a charge transport channel 39 which is sandwiched between upper and lower charge confinement layers, 14,20, has the charge transport channel 39 made of a Strained Layer Superlattice (SLS) comprising alternating deep-well semiconductor layers 40, that provide a deep quantum well depth, and strain relief layers 42 that provide strain relief to prevent dislocations from occurring due to lattice mismatches between the InGaAs layers within the channel 39 and the charge confinement layers 14,20, thereby allowing the overall thickness of the channel 39 to be at least as wide as conventional HACT devices that use a GaAs channel. The strain relief layers 42 may be narrowly sized to allow tunneling of electrons across the entire channel 39 thereby allowing the charge to move as a single group, or alternatively, widely sized to provide separate isolated channels thereby allowing the charge to move in separate groups.

Abstract: A novel channelized, hybrid time- and space-integrating acousto-optic (AO) spectrum analyzer is described. The architecture consists of two acousto-optic cells in a crossed cell configuration. The first acousto-optic cell is a wide bandwidth device that performs space-integrating spectral analysis and channelizes signals according to carrier frequency. The second acousto-optic cell, in conjunction with a modulated source, performs time-integrating spectral analysis of the signal envelope using the chirp algorithm. One possible application of the processor is to determine the carrier frequency and pulse repetition frequency (PRF) of received radar signals.

Abstract: A multiplexed, multicolored video imaging system which comprises a plurality of pulsed lasers to provide input beams, a single acoustic-optical cell to receive the input beams, a transducer to modulate the input beams in the cell, a signal generator to produce sound waves in the cell corresponding to the electrical signals used for a line image; data compressor to decrease the time of propagation of the sound waves in the cell; multiplexer to provide an electrical signal corresponding to each wavelength to separate and sequentially modulate the video signals to provide a multiplexed, modulated output beam, a projection surface and projector to form a line multiplexed, multicolored output on the projection surface.

Abstract: In a raster output scanner, a system for using one original beam and one facet of a rotating polygon to generate a scan line which can be turned on to have three levels of intensity. The original beam is first separated into two beams in a beam splitter. The resultant beams are polarized ninety degrees apart, and directed to the modulator. The beams are a sufficient distance apart so that the A/O modulator can modulate each beam with a minimum of crosstalk. The output beams are then brought together and combined into one beam without optical interference because the beams are polarized ninety degrees apart. The beam can have several levels of intensity and be used to create several levels of gray scale at the output.