Abstract: A solid state electrically variable focal length lens includes a plurality of concentric rings of electro-optical material, wherein the electro-optical material comprises any material of a class of hydrogen-doped phase-change metal oxide and wherein each respective concentric ring further includes a transparent resistive sheet on a first face of the respective concentric ring, wherein the transparent resistive sheet extends along the first face, and a first voltage coupled between a first end and a second end of the transparent resistive sheet, wherein the first voltage may be varied to select an optical beam deflection angle.

Abstract: A system may include a laser source, an acousto-optic modulator (AOM) coupled to the laser source, an atom trap, and an optical body coupled between the AOM and the atom trap and having a plurality of spaced apart optical signal channels etched therein. At least one piezoelectric transducer may be coupled to each of the optical signal channels, and a beam polarization controller may be coupled to the piezoelectric transducers.

Abstract: An actuator system configured to position an object, the actuator system includes a piezo actuator having an actuator contact surface. The piezo actuator is configured to exert a force via the actuator contact surface onto the object. The piezo actuator includes a transparent piezo material. The actuator system further has an optical position sensor configured to measure a position of the actuator contact surface. The optical position sensor is configured to transmit an optical beam through the transparent piezo material to the actuator contact surface. The optical position sensor may form an interferometer.

Abstract: A method is provided for operating an imaging system to maintain a tunable acoustic gradient (TAG) lens at a desired operating state. In a first step, the TAG lens operates using a standard imaging drive control configuration (e.g., a standard drive voltage and duration) during a plurality of imaging drive mode time periods, to achieve a standard imaging state of the TAG lens. In a second step, the TAG lens operates using a regulating adaptive drive control configuration during a plurality of regulating adaptive drive mode time periods, wherein at least one of a different respective TAG lens drive voltage and a different respective TAG lens drive duration is used for different respective regulating adaptive drive mode time periods, based on a monitoring signal that is indicative of a difference between the standard imaging state and a current operating state of the TAG lens.

Abstract: An acousto-optic element array includes: acousto-optic elements each including an acousto-optic generator, a light supply, and a wave transducer; a gate driver that selects an acousto-optic element to be driven from among the acousto-optic elements; an electrical data driver that is connected to an electrical wire and transmits electrical data to an electro-optic modulator configured to control the acousto-optic generator of the selected acousto-optic element; and a wave data driver that is connected to a waveguide and transmits wave data to the wave transducer of the selected acousto-optic element.

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: Provided is an acousto-optic device including an elastic medium; a meta structure formed on a first surface of the elastic medium, and an elastic-wave generating unit which generates an elastic wave in the elastic medium. The meta structure includes a first layer and a second layer that is formed on the first layer. The at least one of the first layer and the second layer includes a predetermined repetitive pattern.

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: A laser beam irradiation apparatus includes a laser beam oscillation unit including a pulse laser beam oscillator for oscillating a pulse laser beam and a cycle frequency setting unit for setting the cycle frequency, an acousto-optic deflection unit for deflecting the optical axis of the pulse laser beam oscillated from the laser beam oscillation section, and a control unit for controlling the acousto-optic deflection unit. The control unit outputs a driving pulse signal having a predetermined time width including a pulse width of the pulse laser beam oscillated from the pulse laser beam oscillator to the acousto-optic deflection unit based on the cycle frequency setting signal from the cycle frequency setting section.

Abstract: A tunable acoustic gradient index of refraction (TAG) lens and system are provided that permit, in one aspect, dynamic selection of the lens output, including dynamic focusing and imaging. The system may include a TAG lens and at least one of a source and a detector of electromagnetic radiation. A controller may be provided in electrical communication with the lens and at least one of the source and detector and may be configured to provide a driving signal to control the index of refraction and to provide a synchronizing signal to time at least one of the source and the detector relative to the driving signal. Thus, the controller is able to specify that the source irradiates the lens (or detector detects the lens output) when a desired refractive index distribution is present within the lens, e.g. when a desired lens output is present.

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 modulator for a Q-switch (300) for a laser includes a monolithic acousto-optic (a-o) medium (311), a series of at least two acoustic transducers (321, 322), bonded spaced apart on the a-o medium, which emit first and second columnar acoustic beams (331, 332). These interact sequentially with an incident optical beam (Light) passing through the modulator. The transducers are oriented so that an optical ray (342) diffracted from the first acoustic column region enters the second acoustic column region at an angle outside the “acceptance angle” of the second acoustical column, i.e. outside the range of incidence angles for which the diffraction efficiency is significant, whereas the remaining light in the zeroth order will undergo further diffraction at the second acoustic column region. This arrangement significantly reduces the amount of light diffracted by the first beam being diffracted back into the zeroth order by the second acoustic beam.

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: A photoelastic modulator, comprising a driving block and a driver transducer for perturbing said block in a predefined direction to establish a standing wave extending longitudinally in said block and hence perpendicularly to said predefined direction. The transducer is affixed to said block at two regions of the transducer mutually displaced in said predefined direction, to minimize the coupling of lateral perturbation perpendicular to the predefined direction. A recess or gap may be provided under the transducer.

Abstract: We disclose acousto-optic modulators that include: (a) an optical element configured to receive an input optical beam that propagates along a first direction; and (b) a transducer extending along the first direction and positioned on one or more surfaces of the optical element, the transducer having a transducer material positioned between two electrodes configured to apply a potential difference across the transducer to cause the transducer to generate an acoustic waveform propagating in a second direction in the optical element, and the input optical beam undergoing diffraction in a region of the optical element that includes the acoustic waveform.

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: A light source system includes a beam source generating a first input beam of light. An anisotropic acousto-optic modulator (AOM) is positioned to receive the first input beam. The AOM includes a plurality of transducers for receiving control signals and generating corresponding acoustic waves that operate on the first input beam to generate first and second output beams with different frequencies and orthogonal linear polarizations. The first and second output beams have a combined optical power that is substantially the same as an optical power of the first input beam for a first input beam with one polarization and for a first input beam with two polarizations.

Abstract: A light source system includes a beam source generating a first input beam of light with first and second beam components. The first component has a first linear polarization and a first frequency. The second component has a second linear polarization and a second frequency. The first and second linear polarizations are orthogonal. An anisotropic acousto-optic modulator (AOM) is positioned to receive the first input beam. The AOM is operable to change the polarization and frequency of the first and the second beam components in response to a control signal, and thereby generate first and second output beams corresponding to the first and second components, respectively.

Abstract: An acousto-optic (AO) device for generating a highly apodized acoustic wave field includes a piezoelectric transducer crystal for emitting an acoustic wave having a ground electrode disposed on one side of the piezoelectric crystal, and a patterned electrode layer disposed on a side of the piezoelectric crystal opposite the ground electrode. The patterned electrode layer includes a continuous region proximate to its center and a discontinuous region, a pattern in the discontinuous region including a plurality of spaced apart features electrically connected to the continuous region. An AO interaction crystal which receives the acoustic wave is attached to the ground electrode or the patterned electrode layer.

Abstract: A communication system uses a beam of light; a beam expanding lens; a lens for collimating the expanded beam into a column of collimated light; a plurality of acoustic transducers to project acoustic emanations perpendicularly to the column of collimated light, wherein each of the acoustic transducers is placed with respect to the column of collimated light to affect a different region of the column; a lens for collecting the collimated light from the collimating lens and light as affected by the acoustic emanation, wherein the collimating lens focuses the collected collimated light at a focal region; an optical filter at the focal region to separate the light as affected by the transducers from light not so affected; and a detector for detecting the light affected by the acoustic emanations.

Abstract: A dynamic beam splitter including a beam deflector having a plurality of operative regions, the beam deflector being operative to receive a laser beam at a first one of the plurality of operative regions, the laser beam passing through the beam deflector, and to selectably direct the laser beam in response to a control input signal to pass through the beam deflector a second time. Methods for splitting a beam and for manufacturing an electrical circuit employing the dynamic beam splitter are also enclosed.

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: 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: 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 acousto optic element comprises optically transparent acousto optic medium having light incoming plane, light outgoing plane facing light incoming plane, transducer joining plane, and inclined plane tilted to transducer joining plane and piezoelectric transducer on which two opposing planes i.e., electrode layers and are formed and the transducer is connected to transducer joining plane of acousto optic medium through one of the electrode layers, wherein a deposited layer or a coating layer is formed on at least one of ultrasonic transducer or the acousto optic medium, the layer preventing ultrasonic waves generated by oscillation of ultrasonic transducer leaking onto acousto optic medium as a leakage-ultrasonic wave and propagating there, thus obtaining a high light-fading ratio.

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: A diffraction-optical component for providing a radiation-diffracting grating structure is proposed, comprising a surface wave device including a substrate 43, a surface wave source 47 excitable with an adjustable frequency for producing surface waves on a surface 45 of the substrate 43 and an interaction region 17 of the substrate surface 45 which is provided for the radiation to interact with a grating structure provided by the surface waves produced.

Abstract: According to the present invention there are provided a transmission line and an optical module having the transmission line, the transmission line having on a dielectric substrate a first signal wiring conductor, a second signal wiring conductor insulated from the first signal wiring conductor, a first electrode disposed near the first and second signal wiring conductors, a second electrode disposed near the second signal wiring conductor, and a ground wiring conductor disposed in adjacency to the second electrode, wherein a passing frequency band can be changed by changing the connection of conductor wires.

Abstract: Micro-eletromechanical devices, substrate assemblies from which the devices can be manufactured, and methods to manufacture the devices are disclosed. The invention combines the advantages of conventional surface and bulk micromachining processes using a sacrificial layer to create an integrated micro-electromechanical system (MIEMS) technology that provides high performance, high yield, and manufacturing tolerance. The devices manufactured according to the present invention include, but are not limited to, pressure sensors, vibration sensors, accelerometers, gas or liquid pumps, flow sensor, resonant devices, and infrared detectors.

Abstract: A multi-channel acousto-optic modulator contains an integrated structure for providing active compensation for transient thermal effects. A plurality of electro-thermal elements in the form of resistive strips are interleaved with acoustic wave launching transducers, to which signals are applied for modulating respective acoustic waves launched into an acousto-optic medium. The resistive strips receive electrical signals that controllably introduce respective thermal energy components into the acousto-optic medium adjacent to the signal launch transducers, in a manner that causes the overall spatial distribution of thermal energy in the acousto-optic medium to have a prescribed characteristic. By establishing an thermal gradient characteristic across all the channels of the RF signal processor, and compensating each channel on an individual basis, the invention effectively compensates for time-dependent variations in heating, resulting in a substantially level thermal behavior.

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 optical reticle substrate inspection apparatus is provided with a laser, a first acoustooptical element which scans a laser beam output from the laser, an a second acoustooptical element which generates a virtual image with a concave lens effect to the laser beam output from the first acoustooptical element. The optical reticle substrate inspection apparatus is further provided with a concave lens arranged on the output side of the laser beam of the second acoustooptical element and an optical system which images the virtual image on a reticle substrate being an object to be inspected. The concave lens magnifies the laser beam in a perpendicular direction to the scanning direction by the first acoustooptical element.

Abstract: The object of the present invention is to effectively utilize the light rays emitted from a light source lamp 1, and, for accomplishing this object, a reflector 2 is made up of a first parabolic reflector 3 designed for reflecting light rays coming from the light source lamp 1 to be outputted as light rays parallel to the optical axis 6, second parabolic reflector 4 designed for reflecting light rays coming from the light source lamp 1 as outwardly inclined parallel light rays, and circular truncated conic reflector 5 for reflecting light rays coming from the second parabolic reflector 4 and outputted as light rays parallel to the optical axis 6. In this fashion, light rays which cannot be outputted due to being in the shadow of the spherical light source lamp can be outputted as light rays parallel to the optical axis 6.

Abstract: An acousto-optic device comprises a first light source for producing a light beam, a light-transmitting material capable of transmitting the light beam along an optical path through the light-transmitting material, a light-absorbing material adjacent to the light-transmitting material, and a pulsed light source capable of directing a pulsed light beam at the light absorbing material so as to produce acoustic waves within the light-transmitting material that cross the optical path of the light beam from the first light source.

Abstract: An integrated high speed driver/modulator assembly includes a driver amplifier assembly having a specified input impedance, such as 50 ohms. The driver/modulator assembly also includes an optical modulator having a modulator transmission line. The impedance of the modulator transmission line is less than the specified input impedance, which results in a reduced V&pgr; for the optical modulator. The reduction in V&pgr; enables the driver/modulator assembly to more effectively support OC-768 and higher data rates of at least 40 Gb/s.

Abstract: An ultrasonic liquid-crystal display comprises a nonpiezoelectric bottom-plate, a piezoelectric substrate on a first surface-part of an upper end-surface of the nonpiezoelectric bottom-plate, at least one dispersive interdigital transducer on the piezoelectric substrate, a nonpiezoelectric upper-plate, a first conducting electrode, with which a second surface-part of the upper end-surface of the nonpiezoelectric bottom-plate is covered, a second conducting electrode, with which a lower end-surface of the nonpiezoelectric upper-plate is covered, and a liquid crystal between the first- and second conducting electrodes. The nonpiezoelectric bottom-plate and the nonpiezoelectric upper-plate have a transparency, respectively. When a first electric signal is applied to the dispersive interdigital transducer, an FM chirp-SAW is excited in the piezoelectric substrate. The FM chirp-SAW transmitted to the liquid crystal causes it cloudy.

Abstract: An apparatus and method for producing a spectrally variable radiation source and systems including same is disclosed. An embodiment of a spectrally variable radiation source is disclosed including a broadband radiation source, a collimating element, a dispersive element, an imaging element, an output aperture and an optional output collimating element. An embodiment of a spectrally encoded infrared chromatograph incorporating the inventive spatially variable radiation source is disclosed. An arbitrary spectrum projector for simulating emission or absorption spectra for chemical and biological agents, as well as projecting calibration and test spectra for characterizing sensors is also disclosed.

Abstract: An acousto-optic tunable filter (AOTF) utilizing phased array transducers for use as dynamically reconfigurable wavelength division multiplexer. The new type of AOTF has the unique capability of simultaneous and independent selection of multi-wavelength signals and separation into multiple output ports. Preferred embodiments of the AOTF are described that provide increased resolution, narrow channel spacing, lower drive power and reduced coherent crosswalk.

Abstract: Apparatus for receiving light containing image-representative information, and low-pass filtering the light. A pellicle is positioned in the path of the light. At least one transducer is coupled with the pellicle and an AC electrical signal is applied to the transducer to establish waves in the pellicle. The waves are operative to low-pass filter the image-representative information in light reflected from the pellicle.

Abstract: An acousto-optic modulator including an ultrasonic medium for controlling light from an optical source through diffraction, two transducers each having one electrode formed on one side thereof, the electrodes being for generating an acousto-elastic wave, and a conductive adhesive layer interposed between the ultrasonic medium and each of the sides of the transducers opposite to the sides on which the electrodes are installed, in order to adhere each of the transducers to the ultrasonic medium.

Abstract: An optically defractive medium of a Bragg cell has a moving grating induced therein in response to acoustic waves propagating in the medium. First and second electro-acoustic transducers coupled to the medium launch first and second acoustic waves toward each other in response to electric excitation of the transducers to produce a moving grating having an amplitude proportional to the difference in the amplitude of the first and second acoustic waves. A laser illuminates the medium and an optical detector array including plural individual detector elements responds to optical energy from the source, as modulated by the moving grating. A processor responds to the detector elements to derive an indication of time difference of arrival of first and second electric signals that respectively drive the first and second transducers.

Abstract: A variable acousto-optic spectrum projector is disclosed. The invention may include a radiation source, an entrance slit, a lens or mirror, a Bragg cell, an arbitrary function generator for driving a transducer of the Bragg cell, another lens or mirror, an exit slit, and a collimating lens. In a first embodiment of the invention, the Bragg cell comprises a Tl3AsSe3 crystal and emits light in the 7 to 11 &mgr;m range (long-wave infrared) with a spectral resolution of between 4.5 and 7 cm−1. In a second embodiment of the invention, the Bragg cell comprises a TeO2 crystal and emits light in the 420 to 720 nm range (visible) with a spectral resolution of between 50 and 80 cm−1.

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: An acousto-optic modulator comprised of an acousto-optic element coated with an anti-reflection layer, and a method of manufacturing the same, are provided. The acousto-optic modulator includes an anti-reflection layer, comprised of at least two coating layers having different refractive indices, formed on the light incident/emitting surface of an ultrasonic medium for modulating a light beam incident from an optical source.

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: An acousto-optic tunable filter based on isotropic acousto-optic diffraction using phased array transducers. The isotropic AOTF provides the advantages of narrow optical passband, low acoustic frequencies, and insensitivity to the input optical polarization. Preferred embodiments of the isotropic AOTFs are described for optimized spectral resolution and diffraction efficiency.

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: The present invention provides a method of ameliorating the effects of misalignment between modulator, and a system using the same. The individual modulator elements are positioned such that a portion of the image produced is generated by both elements. The contribution to the combined output made by each element varies across the overlapped region, with each element making a small contribution to the pixels in the overlapped region at one end and a large contribution to pixels in the overlapped region at the other end. Because the overlapping output regions of the modulators collectively form a portion of the image, any alignment error is effectively spread over the entire overlapped region and is much less noticeable.

Abstract: The disclosed acousto-optic scanning device includes a thin film waveguide of piezoelectric material (2), a transducer (3) for generating surface elastic waves, and a high frequency signal generator (4) for generating high frequency signals to be applied to the transducer. Additionally, the device includes a light source (10), light source driver (11) for driving the light source, a prism or grating input and output light couplers (7, 8 or 27, 28) for introducing light emitted from the light source into the thin film waveguide and for outputting light transmitted through the thin film waveguide therefrom. Further, the device includes non-coupled light photodiode detector array (14) for detecting the position and intensity of light which is not coupled by the output light coupling means, and a signal processor for processing information detected by the non-coupled light detector array and generating control signals to correct the position and intensity of coupled light.