Abstract: In the bias stabilization control using average optical power of signal light, there is a case where a control algorithm (maximum control or minimum control) changes depending on the amplitude of clock voltage, or it becomes out of control. In an optical modulation device for performing CSRZ optical modulation on outgoing light from an optical source, control light inputted from a control light input path is inputted into an LN-MZ optical modulator having traveling-wave type modulating electrodes from a direction opposite to signal light, and the average optical power is detected by a photodetector. A bias-voltage Vb is so generated that this optical power may be minimized, and is applied to a bias input terminal, whereby automatic bias stabilization control is performed.

Abstract: An integrated optical modulator and method for manufacturing thereof are disclosed. The integrated optical modulator comprises a carrier wave band modulator using a double sideband modulation method and an intermediate frequency band modulator using a single sideband modulation method. The carrier wave band modulator and the intermediate frequency band modulator are connected in series. A method for manufacturing an integrated optical modulator comprises preparing a substrate having at least one polarization reversed section, forming a first optical waveguide part and a second optical waveguide part on the substrate, forming a buffer layer over the first and second optical waveguide parts, forming sequentially a first electrode part and a second electrode part over the first optical waveguide part, and forming a third electrode part over the second optical waveguide part.

Abstract: In a representative embodiment, a transmitter of a WDM communication system is equipped with a Mach-Zehnder modulator (MZM) configured to produce an optical signal corresponding to a duobinary data stream by modulating a beam of light passing through the MZM. A three-level electrical signal is applied to the MZM to modulate the light. At the second signal level, the modulator substantially blocks light transmission. At the first and third levels, the modulator transmits light corresponding to the duobinary “?1” and “+1” bits, respectively, such that a relative phase shift between the optical bits is different than 180 degrees, i.e., the phase shift value employed in prior-art optical duobinary modulation.

Abstract: Certain MEMS devices include layers patterned to have tapered edges. One method for forming layers having tapered edges includes the use of an etch leading layer. Another method for forming layers having tapered edges includes the deposition of a layer in which the upper portion is etchable at a faster rate than the lower portion. Another method for forming layers having tapered edges includes the use of multiple iterative etches. Another method for forming layers having tapered edges includes the use of a liftoff mask layer having an aperture including a negative angle, such that a layer can be deposited over the liftoff mask layer and the mask layer removed, leaving a structure having tapered edges.

Abstract: An electro-optic element includes an electro-optic crystal having a birefringent property, and in which a refractive index distribution is generated in accordance with an intensity of an electric field caused inside, a pair of intensity modulating electrodes for applying a voltage for varying the birefringent property of the electro-optic crystal, a pair of scanning electrodes for applying a voltage for varying the refractive index distribution of the electro-optic crystal, and a polarization selection member provided at least on a side of a laser beam emission end face out of a laser beam entrance end face and the laser beam emission end face of the electro-optic crystal, and for selectively transmitting a part with a specific vibration direction out of a light beam emitted from the electro-optic crystal.

Abstract: An optical spike is generated at an arbitrarily selected location within an arbitrary optical link. The optical spike is generated by deriving a spike signal having a plurality of components, and launching the spike signal into the a transmitter end of the optical link. An initial phase relationship between the components is selected such that the involved signal components will be phase aligned at the selected location. In order to achieve this operation, the initial phase relationship between the components may be selected to offset dispersion induced phase changes between the transmitter end of the link and the selected location. One or more optical spikes can be generated at respective arbitrarily selected locations within the link, and may be used for performance monitoring, system control, or other purposes.

Abstract: An apparatus for transmitting at least a digital optical signal with a simultaneous modulation of the amplitude and the phase, the said encoded optical signal having improved spectral efficiency and performances, and being generated by transmitters with simplified scheme; an optical communication system comprising the said apparatus, a transmission line and an apparatus to receive the said optical signal.

Abstract: Disclosed herein is an electro-optical device including: a plurality of electro-optical elements of which the intensity of emitted light is controlled according to drive signals; a plurality of unit circuits which output the drive signals; and a plurality of signal generation circuits which generate control signals according to correction data, wherein the plurality of unit circuits include a plurality of independent unit circuits which generate the drive signals according to the control signal generated by any of the plurality of signal generation circuits and gray scale levels of the electro-optical elements, and a dependent unit circuit which generates the drive signal according to a control signal supplied to a first independent unit circuit and a control signal supplied to a second independent unit circuit among the plurality of independent unit circuits and the gray scale levels of the electro-optical elements.

Abstract: An optical shutter includes a cell having a transparent panel and a hydrophobic transparent insulation panel which are arranged to face each other, a transparent electrode formed on an outer surface of the hydrophobic transparent insulation panel, and an opaque droplet contained in the cell and contacting an inner surface of the hydrophobic transparent insulation panel, wherein the amount of light transmitted is adjusted by changing a contact angle of the opaque droplet with respect to the hydrophobic transparent insulation panel. The opaque droplet may be hydrophobic or hydrophilic. The contact angle of the opaque droplet may be changed by applying an electric field between the transparent electrode and the opaque droplet.

Abstract: According to an aspect of the invention, there is provided a scanning device, which is provided with a light source unit that emits a light beam, a collection optical system that converges the light beam emitted by the light source unit principally in an auxiliary scanning direction, a deflector that deflects the light beam converged by the collection optical system, an image forming optical system that converges the light beam deflected by the deflector onto a scan target surface to form a beam spot scanning in a main scanning direction which is perpendicular to the auxiliary scanning direction.

Abstract: A differential interferometric light modulator and image display system comprises a polarizing beam splitter, a polarization displacement device and a linear array of MEMS optical phase shifting devices to modulate a line image. The polarizing beam splitter acts as both the polarizer and the analyzer in an interferometer. The polarization displacement device divides polarized light from a polarizer into orthogonal polarization components which propagate parallel to one another. The MEMS optical phase shifting device array imparts a relative phase shift onto the polarization components and returns them to the polarization displacement device where they are recombined and sent to the analyzer. The MEMS optical phase shifting devices are electronically controlled and convert electronic image data into actual light modulation.

Abstract: One embodiment relates to a spatial light modulator (SLM) for modulating light incident thereon. The SLM includes a plurality of pixels, each pixel including a plurality of phase shift elements. The SLM also includes a transform filter adapted to control the imaging system to resolve each pixel but not each phase shift element in each pixel. The plurality of pixels are controlled to independently modulate phase and magnitude of light reflected therefrom. Other embodiments are also disclosed.

Abstract: A single side band modulation device includes a first Mach Zehnder interferometer and a second Mach Zehnder interferometer. The first Mach Zehnder interferometer includes at least two output arms, and the second Mach Zehnder interferometer includes at least two output arms. Terminals of the output arms are connected with one another.

Abstract: A method and system for generating colors efficiently. In one embodiment, a start signal for a primary color subcycle may be received. A primary light source used to drive the primary color may be activated if there is data in the primary color's buffer. The primary light source may be deactivated during the primary color subcycle if there is no data in the primary color's buffer. In another embodiment, a highest amplitude signal for one of a plurality of primary colors may be normalized. A drive light source intensity may be adjusted to a percentage of a maximum intensity where the percentage corresponds to a content of the normalized primary color in a frame. The amplitude of all but the normalized primary color may be adjusted proportionally. In another embodiment, a maximum intensity for a light source intensity may be set to a first value. A maximum pixel intensity for each of a plurality of pixels may be set to a second value.

Abstract: An arrangement for removing unwanted amplitude modulation from the output of an electro-optic phase modulator (formed within a silicon-on-insulator (SOI) system) includes resonant filters that are biased on the positive and negative slopes of the response signal. Therefore, as the amplitude response of one filter decreases, the amplitude response of the other filter increases, resulting in balancing the output and essentially eliminating amplitude modulation from the phase-modulated output signal. In one embodiment, ring resonators (formed in the SOI layer) are used to provide the filtering, where as the number of resonators is increased, the performance of the filtering arrangement is improved accordingly.

Abstract: A system and method for addressing an array of MEMS display elements, such as interferometric modulators, from a drive control. A display includes groups of display elements that are addressed with a commonly applied drive signal. In one embodiment, the groups of display elements are configured to have different response times and are driven by pulses of varying length indicative of those response times. In another embodiment, the groups of display elements are configured to have different actuation voltages and are driven by pulses of varying voltage indicative of those actuation voltages.

Abstract: An iterferometric modulator is formed having a dielectric with charge persistence. The interferometric modulator is addressed by a method making advantageous use of the charge persistence property, wherein the interferometric modulator is pre-charged in such a way that the pre-charging is not observable to a viewer, and the actuation voltage threshold of the imod is significantly lowered. Subsequently the interferometric modulator may be actuated with a significantly lower actuation voltage, thereby saving power.

Abstract: A method of forming a display including three conductive layers is described. The display is driven by contacting a third conductive layer and a second conductive layer, wherein the second conductive layer transmits current to the first conductive layer, and an electric field is generated between the first and third conductive layers.

Abstract: An apparatus comprising a control system coupled to an optical modulator. The control system including an Radio Frequency (RF)/dither ratio unit coupled to the optical modulator, wherein the RF/dither ratio unit to modify an amplitude of a dither signal inputted into the optical modulator to maintain a constant ratio between the amplitude of the dither signal and an amplitude of an RF input signal inputted into the optical modulator.

Abstract: The influences on transmission quality caused by chirp and self-phase modulation are at least largely corrected by way of an optimally set operating point of the modulator (2). Suitable criteria are obtained in control loops in order to maintain the optimal setting.

Abstract: The optical transmission apparatus has a Mach-Zehnder optical modulator, a light source for applying an optical signal of a continuous light to the optical modulator, a driving circuit for inputting a driving signal into the optical modulator, a branching filter for taking out a part of an output optical signal, a photodiode for converting the taken-out output optical signal into an electric signal, a band pass filter for extracting a frequency component of a driving signal included in this electric signal, an error signal generator circuit for generating an error signal of a bias voltage that minimizes a value of the extracted frequency component, and a bias voltage control circuit for applying a bias voltage added with this error signal to the optical modulator.

Abstract: With respect to the relative intensity noise (RIN) for inputs to an optical modulator or the signal-to-noise ratio (SNR) for outputs therefrom, the optical modulator modulating coherent lights of different wavelengths obtained by slicing a spectrum of the multi-wavelength light, the shape of a spectrum of a multi-wavelength light is controlled so that predetermined RIN and SNR can be obtained in accordance with transmission system parameters (the type and distance of optical fibers, the number of repeaters), thus enabling design meeting a performance specification for a conventional transmission section using semiconductor lasers.

Abstract: A method and system for generating colors efficiently. In one embodiment, a start signal for a primary color subcycle may be received. A primary light source used to drive the primary color may be activated if there is data in the primary color's buffer. The primary light source may be deactivated during the primary color subcycle if there is no data in the primary color's buffer. In another embodiment, a highest amplitude signal for one of a plurality of primary colors may be normalized. A drive light source intensity may be adjusted to a percentage or a maximum intensity where the percentage corresponds to a content of the normalized primary color in a frame. The amplitude of all but the normalized primary color may be adjusted proportionally. In another embodiment, a maximum intensity for a light source intensity may be set to a first value. A maximum pixel intensity for each of a plurality of pixels may be set to a second value.

Abstract: A light modulator incorporates a polarization sensitive prism and a novel MEMS ribbon device to impart a relative phase shift to polarization components of an incident light beam. A linear array of phase shifting elements in the MEMS device creates a linear image which is scanned to form a two dimensional scene. Alternatively the deflection of each cantilever in a linear array of atomic force microscope cantilevers may be measured simultaneously.

Abstract: An optical modulator is driven by applying, to a first signal electrode, an amplitude-modulated input driving signal waveform, which has a pair of same phase envelope lines, and which has a full width smaller than a potential difference between adjacent two of bias voltages at which an optical intensity of an intensity-modulated output optical signal from the optical modulator takes a minimum value or between adjacent two of other bias voltages at which the optical intensity takes a maximum value.

Abstract: The device includes an oscillator (1) to generate an electrical signal of a predetermined frequency and a signal divider (2) to split the electrical signal into first and second signals. The frequency of the second signal is tripled by tripler (3) and the tripled second signal is recombined with the first signal at signal adder (9) to produce a combined electrical signal. This combined electrical signal drives a Mach-Zehnder modulator (10).

Abstract: A method for modulating the E-field of an optical carrier signal utilizes a Mach-Zehnder modulator having a pair of independently controllable branches. A pair of independent branch drive signals VL(t) and VR(t) are derived. Each branch of the MZ modulator is driven with a respective one of the independent branch drive signals. By this means, a low cost conventional MZ modulator (interferometer) can be used to perform complex modulation of the E-field of the optical carrier. In some embodiments, this functionality is used to facilitate precompensation of optical impairments of an optical communications system.

Abstract: A coherent optical link includes a laser master oscillator operative to generate an amplitude- and phase-stable narrow linewidth optical carrier, a first programmable read-only memory (PROM) having an input for receiving and encoding an M-ary data word, a first digital-to-analog (D/A) converter operative to obtain the amplitude-encoded M-ary data word and output a corresponding analog signal, a Mach-Zehnder intensity modulator that obtains the analog signal and intensity-modulates the carrier based on the analog signal, an optical phase modulator having an input, and an optical waveguide that connects the Mach-Zehnder intensity modulator to the input of the optical phase modulator. The Mach-Zehnder intensity modulator and optical phase modulator may be formed into a single package. A modulation method includes modulating an intensity of an optical signal using a Mach-Zehnder intensity modulator, and then modulating the phase of the intensity-modulated optical signal.

Abstract: A method and apparatus includes receiving light at an intensity modulator. Subsequently, the light is received at an intensity-color modulator that includes at least one Fabry-Perot filter having a tunable optical property.

Abstract: A first optical system (11) has a first beam splitter (211). The first beam splitter (211) splits light arriving through a first optical path (P1) into two light beams, and outputs one light beam to a second optical path (P2) and the other light beam to a third optical path (P3). A second optical system (21) outputs the light output from the first beam splitter (221) to the second optical path (P2) and arriving at the second optical system (21) upon giving the light an intensity change with wavelength dependence and a phase change, and has a second beam splitter (221), first reflecting mirror (223), and second reflecting mirror (222). This makes it possible to provide an optical filter (200) which can realize a characteristic excellent in isolation with a very simple arrangement.

Abstract: A variable optical modulator for optical communication systems using a tunable dynamic grating comprises a gel or membrane layer attached adjacent to a prism communicating light to/from the optical communication system. A substrate has a plurality of individually addressable electrodes and drive means for providing regulated excitation voltage to each of the plurality of electrodes, thereby generating a wave pattern on a surface of the gel or membrane superimposed on an initial state of the gel or membrane layer.

Abstract: An optical signal processor comprises a first input terminal for a pulse signal light with a signal wavelength, a second input terminal for a probe light with, probe wavelength different from the signal wavelength, a first splitter to split the probe light into two portions, an XPM optical device to modulate the one portion of the split output lights from the splitter, a second splitter to split light with the probe wavelength phase-modulated by the XPM optical device into two portions, a first combiner to combine the other portion of the split output lights from the first splitter with the one portion of the split output lights from the second splitter, and a second combiner to combine the other portion of the split output lights from the second splitter with the output light from the first combiner.

Abstract: A method and system for optimization of an optical transmissions signal which is modulated with a binary data signal, wherein a control device ensures that the operating point and the modulation signal of a Mach-Zehnder modulator are set optimally, with the fundamental frequency and/or the first harmonic frequency of the transmission signal being selected for this purpose, and an optimum setting is reached when the amplitude of the fundamental frequency has reached a maximum value and the amplitude of the harmonic frequency has reached a minimum value.

Abstract: A method and system for optimization of an optical transmissions signal which is modulated with a binary data signal, wherein a control device ensures that the operating point and the modulation signal of a Mach-Zehnder modulator are set optimally, with the fundamental frequency and/or the first harmonic frequency of the transmission signal being selected for this purpose, and an optimum setting is reached when the amplitude of the fundamental frequency has reached a maximum value and the amplitude of the harmonic frequency has reached a minimum value.

Abstract: A waveguide having a periodic structure and the excitation of exciton polariton as one form of interactions between radiation fields and matter systems are applied to light switching to provide an optical switch that is excellent in light intensity extinction ratio and operable at a speed in the terahertz order. The optical switch includes a polariton and photon interacting region (5) made of a grating (3) formed on a top face of a transparent substrate (2) and a semiconductor layer (4) with which the grating (3) is covered. The polariton and photon interacting region (5) is irradiated from a free space with a controllable light (7) having a preestablished wavelength and also from a free space with a control light (6) having a preselected wavelength to control the transmissivity of the controllable light (7) through the polariton and photon interacting region (5).

Abstract: An eye protection apparatus includes a selectively darkenable element, such as a liquid crystal panel, and a controller that causes transmission of a darken signal that causes the selectively darkenable element to darken in conjunction with an emission of light, such as intense diffuse light that is used in some medical procedures. Protection against both laser light and diffuse light may be provided in the same eye protection apparatus. The darken signal may be transmitted prior to the emission of the diffuse light, and cause the selectively darkenable element to achieve a darkened state prior to emission of the diffuse light.

Abstract: One embodiment disclosed relates to a system for modulating a plurality of micro-electromechanical (MEM) devices. The system includes a means for providing an amplitude modulation signal to each MEM device at a base frequency and a means for providing a width modulation signal at the base frequency. In addition, the system includes a clock means for providing a higher-frequency clock signal with a frequency that is a multiple of the base frequency. In this embodiment, the width modulation signal for each MEM device indicates at least one position on the higher-frequency clock signal.

Abstract: An optical modulation apparatus includes an optical signal input section, an optical signal propagation path, an optical modulator that modulates the phase of optical signals in at least two of a plurality of optical paths, and a wavelength selective filter that selectively reflects and transmits. Optical signals input via the input section are divided into a plurality of optical paths at a branching point and phase modulated by the phase modulator, that divides the optical path into a plurality of optical paths. Light transmitted by the filter is output via the output section, while light reflected by the filter travels back along the optical path and is again phase modulated by the phase modulator combined at the branching point and output from the input section as an intensity modulated optical signal.

Abstract: One embodiment disclosed relates to a method for driving a micro electromechanical (MEM) device. The method includes generating a high-frequency AC drive signal that is substantially greater in frequency than a resonance frequency of a movable feature in the MEM device, and modulating the amplitude of the high-frequency AC drive signal. A DC-like displacement of the movable feature in the MEM device is achieved by driving the movable feature using the amplitude modulated high-frequency AC drive signal.

Abstract: An optical element capable of performing nonlinear frequency conversion and amplitude modulation simultaneously is disclosed. The optical element includes a monolithically integrated, electrode-coated dispersion nonlinear optical crystal section between two quasi-phase-matched (QPM) nonlinear optical crystal sections. By electrically controlling the relative phase among the mixing waves in the dispersion section, nonlinear frequency conversion and amplitude modulation can be performed simultaneously.

Abstract: An imaging system is disclosed that includes an illumination source, a modulator and a variable Fourier diaphragm. The illumination source produces a first illumination field having a first frequency and a second illumination field having a second frequency. The modulator receives the first illumination field and the second illumination field, and produces a first modulated illumination field and a second modulated illumination fields. The variable Fourier diaphragm selectively passes one of the first modulated illumination field and the second modulated illumination field.

Abstract: A device for the passive conversion of one format to another includes: a laser light source at a predetermined frequency, a line converter configured to produce a fan of light, a movable lens configured to collimate the fan of light, and an array of light modulators placed such that the collimated light is incident on a portion of the light modulators. Vertical pixels of an input image are reproduced on either 1, 2, 3, etc, adjacent light modulators depending on the target image size to produce a modulated light column. Any discrepancy between the modulated light column height and the target image height is compensated for using a zoom lens. The modulated light column is then reflected to a display surface. An entire image is produced by changing the state of the array of light modulators to correspond with each of the vertical columns of the image and sweeping the vertical columns across the display surface.

Abstract: The invention relates to an optical signal transmission system with phase modulation and the implementation method. The system adds a phase modulator in the optical signal-emitting module. The optical pulses after intensity modulation and a high-speed data stream are input to the phase modulator synchronously, where the optical pulses are modulated in phase according to the high-speed data stream into high-speed optical signals with chattering. According to the invention, the phase modulator added in the optical signal-emitting module modulates optical signals in phase, which has been modulated in intensity. Appropriate chattering modulation can depress effectively the non-linear effect in the transmission of optical pulses through the interaction between chromatic dispersion and non-linear effects. Thus, the power input of individual channels is increased effectively, and the passive relay regeneration distance is extended.

Abstract: A Mach-Zehnder Modulator (MZM) pulse generator is provided having an increased power output. Power carved from the output signal in creating the pulses is recycled back to the input of the pulse generator via a feedback arm. Careful design of the length of the feedback arm such that a feedback signal has a propagation time of (2n+1)T/2 to complete one loop (n being a non-negative integer and T being the pulse period) allows a 50% duty cycle to be obtained using a driving frequency of only one half of the pulse frequency.

Abstract: A projector has an illuminating optical system for irradiating white light, a color switching optical system for dividing the white light irradiated by the illuminating optical system into color lights in a time-division manner, a DMD™ for modulating the respective color lights in accordance with an image signal, a projection optical system for projecting the light beam modulated by the DMD, a light-composite optical system for getting the light beam not incident on the projection optical system to be incident again on the DMD and a device controller for controlling the operation of the projector, where the light beam irradiated by the DMD and not incident on the projection optical system is irradiated as a light beam of uniform illuminance distribution by the light-composite optical system and is again introduced on an illumination optical axis to be incident on the DMD, thus enhancing peak luminance of the projected image and achieving high contrast ratio.

Abstract: A method for suppressing distortion in a multi-wavelengths system which uses a Mach Zehnder optical modulator includes adjusting an internal path length mismatch of the modulator and changing an applied voltage, Vb, such that the combination biases the modulator to the required &pgr;/2 phase bias.

Abstract: The invention provides an optical modulator for transmitting data encoded in NRZ mode by modulating the intensity of a light signal, the modulator including means for shaping the light signal including shaping means for producing a signal of low bandwidth from an input control signal, and a laser modulator having a transfer function favoring the extinction time of the resulting light signal.

Abstract: An electro-optic modulator having a continuously adjustable chirp is provided. Optical signals input into the electro-optic modulator are divided into portions which are phase modulated in opposite senses, one portion imparted with a positive chirp and the other with a negative chirp. Variable couplers are used to adjust (by way of adjusting their coupling ratios) the amount of power allocated between the optical signals contributing to the positive chirp and the power of signals contributing to the negative chirp so that when the optical signals are combined an optical signal with an adjustable chirp is produced.

Abstract: A light-modulating system, includes: a light source for emitting a sequence of light pulses at a period Tp; a light modulator having a variable-width switching profile with rise and fall times Tr and Tf respectively, wherein the greater of Tr and Tf is greater than Tp, the light modulator modulating the sequence of light pulses; and a controller for controlling the width of the variable-width light switching profile.

Abstract: A method of mapping diagonal rows and columns of two-dimensional grid elements to rectangular rows and columns of two-dimensional grid elements. The method is of particular use with a spatial light modulator in optical equalization application.