Abstract: The invention relates to an interleaver circuit (10, 10?) for interleaving optical signals, comprising a first and a second input port (12, 14), an output port (16), a first optical filter (18; 18?) that has a first filter function with periodic passbands (32, 34, 36) and is connected to the first input port (12), a second optical filter (20; 20?) that has a second filter function with periodic passbands (38, 40) and is connected to the second input port (14), and an optical interleaver (22). The latter comprises a multiplexing port (23) connected to the output port (16) and two de-multiplexing ports (24, 26) connected to the first input port (12) via the first optical filter (18; 18?) and the second optical filter (20; 20?), respectively. At least one optical filter (18, 20; 18?, 20?) is tunable such that the passband frequencies are collectively shiftable without altering the periodicity of the filter function.

Abstract: This invention relates to an acousto-optical tunable filter generally of the kind described in U.S. Pat. No. 6,266,462. More specifically, the invention relates to a filter and its construction, the filter including a support, first and second mounts at spaced locations on the support, an optical fiber having first and second mounted portions secured to the first and second mounts respectively and a filtering section between the first and second mounted portions, a signal generator operable to generate a periodic signal, and an electro-acoustic transducer having a terminal connected to the signal generator and an actuating portion, the electric signal causing vibration of the actuating portion, and the actuating portion being connected to the filtering section so that the vibration generates a transverse wave traveling along the filtering section. The filter has an improved damper to more effectively dampen waves traveling along the filtering section.

Abstract: A technique for performance-monitoring of a standard SONET signal involves first converting the optical signal to an electrical signal, removing in the framing signal time slot the framing signal for leaving only the framing signal noise in such time slot, and separating the framing signal noise from the data signal for viewing as a measure of the quality of the SONET signal.

Abstract: An optical arrangement for directing illumination light to a sample and for directing the detection light proceeding from the sample to a detector has a spectrally selective influencing means in the beam path of the detection light, which influences the polarization properties of the illumination light reflected or scattered from the sample in such a way that a polarizing beam splitter splits the illumination light reflected or scattered from the sample out of the detection light.

Abstract: A direct-view optical microscope system is provided which uses high-energy light from a phenomenon known as non-resonant Raman scattering to illuminate a living biological specimen. One embodiment of the system combines two discrete light sources to form a combined incident light source for the microscope. The system includes a method and apparatus for modulating the intensity of the scattered light when two light waves are combined to produce the incident light. By varying the frequency of the two source light waves, the intensity of the combined Raman-scattered light can be modulated to achieve finer resolution.

Abstract: A scanning microscope that defines an illumination beam path and a detection beam path, having an objective that is arranged in both the illumination beam path and the detection beam path, is disclosed. The scanning microscope is characterized by an interchangeable module that is also arranged in the illumination beam path and a detection beam path and that separates the illumination beam path and detection beam path at a fixed angular relationship to one another and comprises at least a first acoustooptical component. Also disclosed is an optical element having at least three ports.

Abstract: The invention relates to a method of activating an optical communication system comprising a plurality of optical amplifiers having an optical amplifier, between optical transmission lines in which wavelength-division multiplex optical signals are transmitted. The method comprises steps of: generating a desired slope in a desired wavelength range of a gain wavelength curve of the optical amplifier; adjusting an output of the optical amplifier to a desired output level; performing the above two steps in a plurality of optical repeater stations, the steps being carried out in sequence from the first to the last optical repeater stations; and adjusting a level in each optical signal in the wavelength-division multiplex optical signal so as to have substantially constant optical signal-to-noise ratios in the optical signals to be received. Activating the optical communication system according to this procedure allows proper execution of gain slope compensation, output control, and pre-emphasis control.

Abstract: An aspect of the present invention includes a method to print pattern with improved edge acuity. In one embodiment a method for printing fine patterns comprising the actions of: providing an SLM and providing a pixel layout pattern with different categories of modulating elements, the categories differing in the phase of the complex amplitude. Other aspects of the present invention are reflected in the detailed description, figures and claims.

Abstract: Methods to improve the optical properties of Bragg gratings are disclosed. A first method includes a post correction of the refractive index profile by applying an average index correction thereto. The average index correction is obtained through an analysis of the defects of the refractive index profile characterised through a reconstruction thereof. A second method includes a pre-correction to the refractive index profile by characterising the defects of a test grating, and again calculating an average index correction based thereon. Further gratings are then made using a corrected refractive index profile.

Abstract: This invention includes an Acousto-optical tuning device by employing the TeO2 in share mode, non-collinear and in high RF frequency (or large Bragg's deflection region), it is able to achieve the telecomm worthy tunable filter that provides high tuning speed, no-moving parts, very narrow filter line-width (0.2 nm for instance) and with miniature size practical for a optical telecom active module. This tuning characteristic is achieved by taking the particular advantages that the angle of incidence (AOI) and angle of diffraction (AOD) are divergent in a frequency range just suitable for a shorter wavelength application required by modern telecommunication systems while the acoustic wave decay in this frequency range can be properly managed to achieve the design goals. Furthermore, by generating a diffracted beam with larger AOD, implementation of filtering for optical propagations of different wavelengths can be conveniently selected.

Abstract: This invention includes an Acousto-optical tuning device by employing the TeO2 in share mode, non-collinear and in high RF frequency (or large Bragg's deflection region), it is able to achieve the telecomm worthy tunable filter that provides high tuning speed, no-moving parts, very narrow filter line-width (0.2 nm for instance) and with miniature size practical for a optical telecom active module. This tuning characteristic is achieved by taking the particular advantages that the angle of incidence (AOI) and angle of diffraction (AOD) are divergent in a frequency range just suitable for a shorter wavelength application required by modern telecommunication systems while the acoustic wave decay in this frequency range can be properly managed to achieve the design goals. Furthermore, by generating a diffracted beam with larger AOD, implementation of filtering for optical propagations of different wavelengths can be conveniently selected.

Abstract: An optical modulator includes an optical waveguide, a modulating electrode, a conductive layer, an electric signal input section, and connector members. At least a portion of the optical waveguide is made of an electro-optic material. The modulating electrode includes a first conductor line and a second conductor line, which are coupled together electromagnetically, and applies a modulating electric field to a portion of the optical waveguide. The conductive layer forms a first microstrip line with the first conductor line and a second microstrip line with the second conductor line, respectively. Through the electric signal input section, an RF modulating signal is supplied to the modulating electrode. The connector members connect the first and second conductor lines together at both ends. In this optical modulator, the first and second conductor lines function as an odd-mode resonator for the RF modulating signal.

Abstract: An optical tunable filter that includes a thin-film filter for band-passing at least two bands of wavelengths. The tunable filter further includes a tunable band-passing device tunable over the at least two bands for tuning to a tunable pass-band spectrally overlapped with one of the at least two bands. The tunable band-passing device further includes an Acousto-optical cell tunable with acoustic wave signals. The thin-film filter cooperating with the tunable band-pass device for generating a tunable output waveform that has substantially a square waveform spectrally corresponding to the at least two bands. The thin-film filter further cooperates with the tunable band-pass device for generating a tunable output waveform having substantially a square waveform over a spectral range of a C-band, an L-band and an S-band.

Abstract: A colored lighting separating device and a single-panel color image display apparatus using the same include a colored light separator having a plurality of dichroic filters to separate incident light into a plurality of colored light beams and a driving device which moves the colored light separator to scroll the separated colored light beams. The colored light separating device performs color scrolling by driving the colored light separator itself so that the structure of the colored light separating device enabling color scrolling is simplified, continuity and consistency of the color scrolling are guaranteed, and the scrolling speed of color bars are kept constant.

Abstract: Systems and methods for scanning a beam of light over a specimen are provided. A system may include a pre-scan acousto-optical deflector (AOD) configured to deflect a beam of light, a second AOD configured as a traveling lens to focus the scanning beam, a relay lens, and an objective lens. The relay lens may be centered on the scan line produced by the second AOD, while the objective lens may be substantially de-centered with respect to the relay lens to produce a telecentric scanning spot with no field tilt. The system may modulate the amplitude of the sound wave in the first AOD to compensate for attenuation in the second AOD. The system may pre-fill one chirp packet in the second AOD while another chirp packet is scanning to substantially reduce a delay between consecutive scans.

Abstract: An AOTF drive method for driving a plurality of AOTFs connected in tandem comprises: separating a plurality of RF signals in advance into a plurality of groups; batch-branching the RF signals of each group in accordance with the number of steps of the AOTFS; and batch-adjusting the phases of the individual branched RF signals. As a result, this makes it possible to reduce the number of phase shifters compared to the prior art while maintaining the effectiveness of suppressing beats in the AOTFs.

Abstract: The invention provides a remote control device of an acousto-optic tunable filter, which comprises an acousto-optic tunable filter interpolated in an optical transmission line, capable of controlling an output state of an input light signal by being supplied with a surface acoustic wave control signal through a control port; a surface acoustic wave control signal source to generate the surface acoustic wave control signal, which is provided at a remote place from the acousto-optic tunable filter; and a control unit that receives an information of the surface acoustic wave control signal from the surface acoustic wave control signal source through remote transmission means, and supplies the surface acoustic wave control signal to the control port of the acousto-optic tunable filter.

Abstract: Device whereby one or more bands of optical wavelengths may be selected for further transmission. All light within the optical bandwidth of operation is first coupled from the core mode of an optical fiber to a specific cladding mode by a chirped broadband cladding mode coupler. These cladding mode lightwaves then enter a narrow-band core mode coupler whereby selected optical bands of wavelengths, tuned by the tension on the optical fiber, are re-coupled back into the core of the optical fiber. The chirped broadband cladding mode coupler is isolated from the narrow-band core mode coupler by an acoustic absorber to limit the acoustic interaction between them.

Abstract: To provide a process of successively forming from an EL layer, a cathode, a barrier layer and a cover layer in the same multi-chamber. By using a same film deposition method to form the EL layer and the cover layer, as shown in FIG. 1A, the EL layer, the cathode, the barrier layer, and the cover layer can be formed in the same multi-chamber in succession. Thus, as shown in FIG. 1B, a sealed structure of an EL element can be formed.

Abstract: An optical channel monitor (OCM) or filter for analyzing an incident light carrying a number of narrow band signal channels such as WDM or DWDM channels. The OCM or filter use an acousto-optic tunable filter to receive and refract from an incident light a refracted light such that the refracted light contains a test channel with a center frequency &ngr;0. A first birefringent element is provided for filtering from the refracted light a first polarized light and a second polarized light orthogonal to the first polarized light. The transmission curves are engineered such that the transmissions of the first and second polarized light are substantially equal at the center frequency &ngr;0 of the test channel. The OCM or filter has a second birefringent element for filtering from the first polarized light a first polarized portion and a second polarized portion.

Abstract: The present invention aims at providing a control method and a control apparatus for controlling variable selected wavelengths at respective stages with high accuracy and reliability, to obtain desired wavelength characteristics, in a multi-staged band rejection type optical wavelength variable filter.

Abstract: The present invention aims at providing a control method and a control apparatus for controlling variable selected wavelengths at respective stages with high accuracy and reliability, to obtain desired wavelength characteristics, in a multi-staged band rejection type optical wavelength variable filter.

Abstract: A novel, cost effective optical filter is employed for photosensors used in ultraviolet-based water purification systems. Optically tuned to specifically eliminate the non-germicidal wavelength polychromatic emissions from mercury lamps, this unique optical filter approach significantly reduces the cost in manufacturing reliable water purification systems employing ultraviolet light.

Abstract: The present invention includes a flexure mount. The tunable filter further includes an actuator coupled to the flexure mount, wherein the actuator elastically perturbs the flexure mount. The tunable filter also includes a Mach-Zehnder device coupled to the flexure mount. The Mach-Zehnder device includes a first tapered coupling region; a second tapered coupling region spaced apart from the first tapered coupling region; and a phase shift region disposed between the first and second tapered coupling regions.

Abstract: A reconfigurable optical interleaver/deinterleaver device combines/separates a pair of optical input signals from and/or to an optical WDM input signal. The interleaver device includes a spatial light modulator having a micro-mirror device with a two-dimensional array of micro-mirrors that flip between first and second positions in a “digital” fashion in response to a control signal provided by a controller in accordance with a switching algorithm and an input command. A pair of collimators, diffraction gratings and Fourier lens collectively collimate, separate and focus the optical input channels and optical add channels onto the array of micro-mirrors. Each optical channel is focused on a plurality of micro-mirrors of the micro-mirror device, which effectively pixelates the optical channels.

Abstract: The present invention provides to a front panel for a display in which the light transmittance of the front panel at a wavelength of 450 nm is higher than the light transmittance at a wavelength of 525 nm and the light transmittance at the wavelength of 525 nm is higher than the light transmittance at a wavelength of 630 nm. The front panel for a display of the present invention improves image contrast and color reproducibility of the display, when it is installed at the front side of a projection television receiver, a liquid crystal display, a plasma display, or the like.

Abstract: An object of the invention is to provide an acousto-optic tunable filter (AOTF) that realizes filter characteristics where the wavelength characteristics in the vicinity of a selected center wavelength are smooth, and the bandwidth thereof is sufficiently narrow. To this end, an AOTF of the invention has a construction where a mode coupling section and a wavelength characteristic flattening section provided with an optical filter configuration for selecting an optical signal based on mode conversion using the acousto-optic effect, are respectively connected via a mode branching device. The mode coupling section mode converts an optical signal corresponding to a selected wavelength, and the wavelength characteristic flattening section again mode converts only the optical component of a part of the selected optical signal mode converted in the mode coupling section in the vicinity of a center wavelength thereof.

Abstract: An object of the invention is to provide an acousto-optic tunable filter (AOTF) that realizes filter characteristics where the wavelength characteristics in the vicinity of a selected center wavelength are smooth, and the bandwidth thereof is sufficiently narrow. To this end, an AOTF of the invention has a construction where a mode coupling section and a wavelength characteristic flattening section provided with an optical filter configuration for selecting an optical signal based on mode conversion using the acousto-optic effect, are respectively connected via a mode branching device. The mode coupling section mode converts an optical signal corresponding to a selected wavelength, and the wavelength characteristic flattening section again mode converts only the optical component of a part of the selected optical signal mode converted in the mode coupling section in the vicinity of a center wavelength thereof.

Abstract: A process for configuring a tunable MOEMS filter train comprises determining a spectral response of a MOEMS tunable filter. A spectral separation between different order modes, or free spectral range, is then determined for the filter. This information is then related to a mode size of a desired mode of the tunable filter. With this information, lenses for the optical train are provisioned, and then installed so that light is launched into the optical filter at the desired mode size to thereby maximize the SMSR of the filter train.

Abstract: The present invention has applications that include detecting color variation in a region, for example, color variations due to temperature changes in an area of ocean water, and, in a more specific application, detecting bioluminescence of certain organisms known to attach themselves to various objects. In one aspect of the invention, an acousto-optic tunable filter hyperspectral imaging system is moved across the region to collect a series of images in which each image represents the intensity of light at a different wavelength. In one embodiment, the acousto-optic tunable filter hyperspectral imaging system includes a motion platform for positioning the acousto-optic tunable filter hyperspectral imaging system over successive Y-coordinates of a region in a direction substantially parallel to a direction of motion of the motion platform.

Abstract: An dynamic optical filter 10 is provided to selectively attenuate or filter a wavelength band(s) of light (i.e., optical channel(s)) or a group(s) of wavelength bands of an optical WDM input signal 12. The optical filter is controllable or programmable to selectively provide a desired filter function. The optical filter 10 includes a spatial light modulator 36, which comprises an array of micromirrors 52 that effectively forms a two-dimensional diffraction grating mounted in a retro-reflecting configuration. Each optical channel 14 is dispersed separately or overlappingly onto the array of micro-mirrors 52 along a spectral axis or direction 55 such that each optical channel or group of optical channels are spread over a plurality of micromirrors to effectively pixelate each of the optical channels or input signal.

Abstract: In a light-emitting diode, a phosphor layer 6 containing a phosphor is laid on top of translucent sealing resin 8 having a light-emitting diode element 3 sealed in it, and then, by shaving the phosphor layer 6, the hue of the light emitted by the light-emitting diode is adjusted. This makes it possible to adjust the hue of the light emitted by individual light-emitting diodes to obtain a uniform hue. For quick and easy adjustment of the hue, the phosphor layer 6 is shaved preferably by laser beam machining.

Abstract: An acousto-optic variable-wavelength TE/TM mode converter is configured by comprising an optical waveguide, a coupled acoustic waveguide composed of two acoustic waveguides, comb electrodes arranged at the acoustic waveguides, and surface acoustic wave absorbers arranged at the acoustic waveguide. If high-frequency electric signals having different frequencies are applied to the electrodes, surface acoustic waves W11 and W12 occur on the surface of the piezoelectric substrate, meander and propagate in the substrate, and are finally absorbed by the absorbers. The intensity distributions of the surface acoustic waves W11 and W12 are distributions where the intensity is high in a middle portion of the optical guide, and low at both ends of the optical waveguide. The peak positions of the intensities are different, and the bases of the distributions partially overlap between the two absorbers.

Abstract: An object of the present invention is to provide a polarization optical article comprising a polarizer incorporated therein which provides views through sunglasses, goggles, lenses, or the like with colors close to natural colors by correcting a color hue with substantially grayish coloring.

Abstract: Fabry-Perot filters are disclosed. having micro-electro-mechanical systems (MEMS) parts operable for tuning of the filters. The filters of the present invention are particularly useful in WDM and DWDM optical communication systems for multiplexing and demultiplexing channels of electromagnetically-carried data traversing the system. The filter can be miniaturized by etching or photolithographing the filter on silicon wafers utilizing MEMS technology. A MEMS device fabricated on the wafer is operative for moving a variably positioned mirror to change the length of the cavity or etalon of the Fabry-Perot filter, thereby tuning the filter to multiplex or demultiplex the channels.

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: The present invention pertains to a polarization independent tunable acousto-optical filter and the corresponding method. The filter diffracts an input light beam into a first input light beam unaffected by acoustic waves and a second input light beam affected by acoustic waves. A polarization beam displacer/combiner is employed to separate the input light beam into two orthogonal beams. Several polarized rotators are used to rotate the polarization of light by 90 degrees. An acousto-optical device makes the polarization of light with a particular wavelength rotate by 90 degrees. The two beams are then properly combined to form orthogonal beams. The filtering method has nothing to do with the polarization of the incident light. The filter has such advantages as a high extinction ratio, a small volume and a lower cost.

Abstract: A polarization mode dispersion generator for generating polarization mode dispersion (“PMD”) spectra is provided. The generator includes a plurality of birefringent stages, each stage including a differential group delay (“DGD”) element and a phase-shifting element. The generator is capable of inducing an amount of polarization mode-mixing between at least one adjacent pair of stages. The shape of a PMD spectrum can be preserved while frequency shifting the spectrum in either direction. Alternatively, the shape of the PMD spectrum can be changed without frequency shifting.

Abstract: The present invention pertains to a polarization independent tunable acousto-optical filter and the corresponding method. The filter diffracts an input light beam into a first input light beam unaffected by acoustic waves and a second input light beam affected by acoustic waves. A polarization beam displacer/combiner is employed to separate the input light beam into two orthogonal beams. Several polarized rotators are used to rotate the polarization of light by 90 degrees. An acousto-optical device makes the polarization of light with a particular wavelength rotate by 90 degrees. The two beams are then properly combined to form orthogonal beams. The filtering method has nothing to do with the polarization of the incident light. The filter has such advantages as a high extinction ratio, a small volume and a lower cost.

Abstract: Inorganic crystals having one or more species of dopant ions which are photo-reactive are used as visible and or infrared light optical limiters to protect against laser radiation exposure while permitting passage of the visible and or infrared light spectrum at least until exposed to high energy laser radiation. The dopant ions are selected from ions of transition metals. The exposure of these ions within the transparent crystalline matrix either photo-ionize or are elevated to an excited state and thereby absorb or otherwise attenuate the passage of the laser beam radiation sufficiently to protect human eyes or photo-sensitive equipment. The crystals may be fabricated into such items as lenses for use in eyeglasses or on shields of flight helmets to protect the eyes of aircraft pilots.

Abstract: A double-passage acousto-optical device including an acousto-optical switch having a first polarization conversion region connected between first input and output ports, and a second conversion region connected between second input and output ports; and an optical combination connected between the first output port and the second input port via optical fibers and including an optical isolating element. The double-passage acousto-optical device may alternately include an acousto-optical switch including a single polarization conversion region connected between first input and output ports and also connected between second input and output ports. A bandpass filter, a notch filter, and add/drop and a tunable laser generator may be formed using the acousto-optical device.

Abstract: A remote control device of an acousto-optic tunable filter includes an acousto-optic tunable filter, a surface acoustic wave control signal source and a control unit. The acousto-optic tunable filter receives an output light signals from an optical transmission line and has a control port to control and outputs state of the light signal received from the optical transmission line, based on a surface acoustic wave control signal received through the control port. The surface acoustic wave control signal source generates the surface acoustic wave control signal and is provided at a remote place from the acousto-optic tunable filter. The control unit receives information regarding the surface acoustic wave control signal generated by the surface acoustic wave control signal source and supplies the surface acoustic wave control signal to the control port of the acousto-optic tunable filter.

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: In an OADM system, an OADM device includes an AOTF. The AOTF can select an optional wavelength by changing the frequency of an RF signal to be applied. An optical signal having a specified wavelength can be dropped from a wavelength-multiplexed optical signal input from an input terminal, or a wavelength-multiplexed optical signal input from an add port can be multiplexed with a through optical signal. However, considering the increase in coherent cross talk, the AOTF should be exclusively used for dropping in an actual device configuration. Otherwise, a drop optical signal is branched by an optical coupler with the wavelength selected by a tributary station. Thus, the wavelength selected by the tributary station can be extracted by the AOTF from the through optical signal.

Abstract: A glass substrate for a display with a thickness of from 0.3 to 6 mm, which has an average WCA (filtered center line waviness: JIS B0651) of from 0.03 to 0.5 &mgr;m measured with a contact-type surface roughness measuring instrument using a phase compensation 2RC zone filter with a cutoff value of 0.8 to 25 mm over a measuring length of 200 mm.

Abstract: A Galileo type stereomicroscope permits an observer to change its eye-level by varying a space between an objective lens and a pair of a focal variable magnification lenses. The Galileo type stereomicroscope satisfies following condition: Z>f0/3, where Z denotes a variable range of the eye-level and f0 denotes a focal length of an objective lens to be used. The objective lens for the Galileo type stereomicroscope keeps imaging quality up to a periphery of an image field while the eye-level is changed.

Abstract: The present invention relates to an optical filter comprising a simple structure which easily realizes slope control of loss spectrum in a signal wavelength band as a gain equalizer. The optical filter comprises a first Mach-Zehnder interferometer constituted by a first part of a main optical line, a first auxiliary optical line, and first and second optical couplers which optically couple the main optical line and first auxiliary optical line to each other. The optical filter further comprises a second Mach-Zehnder interferometer constituted by a second part of the main optical line, a second auxiliary optical line, and third and fourth optical couplers which optically couple the main optical line and second auxiliary optical line to each other.

Abstract: A computer-readable signal bearing medium (10) has components (11, 21, 31) which act via a data processor (86) in an imaging system having an acoustic energy source (81) and a birefringent detector (84, 70) to record first data (14) from a first portion (61) of an object (60), the first portion attenuating first acoustic energy (12) at least part way to a first attenuation maximum (13, 43) along a first acousto-optic response (41) of the birefringent detector; to record second data (24) from a second portion (62) of the object, the second portion attenuating second acoustic energy (22) at least part way to a second attenuation maximum (23, 53) along a second acousto-optic response (51) of the birefringent detector; combines the data (32), and outputs a result.

Abstract: Disclosed is a laser modulating optical system, which includes an argon laser that emits at a plurality of peak wavelengths, an acoustooptic modulator (AOM) that changes a direction of an emergent light by diffraction caused by input ultrasonic wave to take out a diffracted beam as a modulated beam, and a correction optical system. The correction optical system includes one pair of wedge prisms located in a parallel laser beam at the incident side of the AOM. The wedge prisms are arranged with a predetermined space therebetween. The apex of one prism is opposite in direction to the apex of the other prism to have the opposite chromatic dispersions to each other. The wedge prisms are designed to coincide the optical paths of two peak wavelengths that are deviated to each other due to a variation of the diffraction angle of the AOM.

Abstract: A polarization-independent polychromatic light modulator applies one or more pairs of predetermined RF drive frequencies to an acousto-optic transducer of an acousto-optic modulator body upon which a single beam of randomly polarized or unpolarized polychromatic input light is incident. No precursor polarization separation elements are employed. For each optical wavelength to be extracted from the incident beam, two RF drive frequencies are employed. The acoustic waves launched into the acousto-optic medium by the application of the two frequencies of a given RF drive frequency pair produce respective +1 and -1 order output beam components of the selected output wavelength (as well as a zeroth order beam for that wavelength).