Abstract: A high-speed optical amplifier is considered to be an important optical device because of an increasing demand of routing, which is accompanied by an increase in complexity of networks. It is difficult to satisfy a response performance by related-art techniques, and there has been a problem in achieving a high-speed response performance of 10 microseconds or less. An optical amplifier according to the present invention includes: an input monitor means 500; an optical amplification means 310 including an optical amplification medium 300, and a control means 400 for performing feed-forward control. When the optical amplification means is controlled by the feed-forward control in response to a signal of the input monitor means 500, an overshoot signal is applied as a control signal so that a slow response performance specific to the optical amplification medium has been improved, and thereby high-speed response performance has been achieved.

Abstract: A method includes generating a plurality of beams that each illuminate a separate portion of a spatial light modulator. The spatial light modulator has a first dimension of a first length and a second dimension of a second length. Each of the beams spans a portion of the first length of the first dimension and a portion of the second length of the second dimension. The method also includes scrolling the plurality of beams along the second dimension of the spatial light modulator while maintaining at least a first gap between each of the plurality of beams.

Abstract: Methods and apparatuses for controlling a bias point voltage for an external optical modulator are provided. A control loop is used to adjust a bias signal applied to an external modulator by determining unwanted signals at a predetermined frequency received by an optical receiver of the control loop and accounting for these unwanted signals when determining the bias point voltage.

Abstract: An optical package is provided comprising a laser diode, coupling optics, a wavelength conversion device, and a multi-component mounting frame. The coupling optics comprises a first lens component that creates a virtual magnified image V of the waveguide of one of the opposing facets with a magnification factor M1 and a second lens component that creates a focused image of V at the remaining opposing facet with a magnification factor M2. The virtual magnified image V is outside of the interfacial waveguide-to-waveguide optical path of the package and the multi-component mounting frame comprises first and second frame components that independently fix the relative alignment of the first and second lens components. The first and second frame components are secured to each other such that angular misalignment between the first and second frame components originates along a fixation interface H that is outside of the interfacial waveguide-to-waveguide optical path.

Abstract: A projection type display apparatus is provided that is safe even when a person looks directly into a laser beam. A laser operation control unit sets the output power of at least one laser source so that intensity A (mW/mm2) of the laser beam on at least one spatial light modulation element satisfies relationship of A<686×B2 when numerical aperture B on image side of an illumination optics system is set.

Abstract: In order to avoid firstly decidedly periodic loading of an output-buffered constant current power supply unit (17) and secondly physiological loading as a result of only intermittently appearing primary colors (R, G, B) when activating mixed light color loci, primary color light sources (11R, 11G, 11B) are energized in pulse-width-modulated fashion periodically in a temporally offset manner, but in addition in each instance, in time-parallel fashion with respect thereto, also those primary color light sources of further primary color light sources (11R, 11G, 11B) whose primary colors in the cyclic activation are not being energized at that time are likewise energized in a pulse-width-modulated manner (FIG. 2).

Abstract: A method of piloting an optical polarization controller including a cascade of variable polarization transformers that can be driven individually to realize overall a polarization transformation between an input optical signal and an output optical signal with each transformer having predetermined maximum and minimum end driving limits. For each transformer the method includes cyclically the steps of finding an error signal output to the controller and driving a first transformer polarization variation by a predetermined amount CS in one of the two directions to check whether with this variation the error signal is reduced and, if not, driving in the opposite direction. The decision of which of the two directions to drive first is made each time and is not fixed. Equipment in accordance with the method is also described.

Abstract: A system and method for locking the relative phase of multiple coherent optical signals, which compensates for optical phase changes induced by vibration or thermal changes in the environment.

Abstract: A method utilizes a dynamically controllable optical element that receives an electrical field, which changes an index of refraction in at least one direction within the optical element. The change in index of refraction imparts a change to a beam of radiation passing through the optical element. The electric field is controlled by a feedback/control signal from a feedback system that includes a detector positioned proximate an image plane in the system. The optical element can be positioned in various places within the system depending on what light characteristics need to be adjusted, for example after an illumination system or after a light patterning system. In this manner, the optical element, under control of the dynamic electric field, can dynamically change its propagation characteristics to dynamically change either a beam of illumination from the illumination system or a patterned beam of radiation from the patterning system, such that they exhibit desired light characteristics.

Abstract: An integrated control system for a laser and Mach-Zehnder interferometer are disclosed and may include configuring a bias point for low-speed control of an optical modulator utilizing control circuitry integrated on the same CMOS die. The optical modulator may be differentially monitored. A laser source for the modulator may be controlled utilizing monitor photodiodes via optical taps on outputs of the modulator, or utilizing a monitor photodiode on one output port of the modulator, which may comprise a Mach-Zehnder interferometer. An error signal may be generated by subtracting monitor photodiode signals from optical taps on output ports of the modulator. The bias point of the modulator may be adjusted by minimizing the error signal. Calibration time of the bias point may be reduced utilizing electronic data inversion. An output of the modulator may comprise a Y-junction and a single monitor photodiode may measure both branches of the modulator.

Abstract: The optical modulator branches an input light into (2×N) lights in an optical branching section, and then phase modulates each of the branched lights in (2×N) phase modulating sections, and couples the phase modulated lights in an optical coupling section and generates a quadrature amplitude modulated (QAM) signal light having a 4N value. At this time, a relative difference of optical phases of the phase modulated lights is variably adjusted by an optical phase adjusting section. Moreover, a power ratio of the phase modulated lights is variably adjusted with an optical power adjusting section. As a result, it is possible to output 4N QAM signal light, with good signal quality.

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: There is disclosed an illumination optical system which illuminates an illumination target surface on the basis of light from a light source, said illumination optical system comprising, a spatial light modulator having a plurality of optical elements arrayed two-dimensionally and being individually controllable, a distribution forming optical system which forms a predetermined light intensity distribution on an illumination pupil of the illumination optical system on the basis of light having traveled via the spatial light modulator, and a control unit which integrally controls postures of a group of optical elements according to a shape of the predetermined light intensity distribution formed on the illumination pupil, out of the plurality of optical elements.

Abstract: A projection apparatus for scanningly projecting an image onto an image field by means of a radiation beam includes a modulator for modulating an intensity of the radiation beam such that the intensity of the radiation beam changes in a time interval during which a scan point to which the radiation beam is directed sweeps a pixel of the image field.

Abstract: The present invention provides an optical transmission device 100 capable of solving the problem of an unnecessary residual sideband components to thereby obtain a high-quality optical intensity-modulated signal in a case where an SSB optical modulation section 20 has wavelength dependence and a manufacturing error. In the optical transmission device 100, where the SSB optical modulation section 20 cannot evenly branch the intensity of the optical carrier into two routes of optical waveguide, the amplitude adjusting section 62 adjusts the amplitude of an electric signal that changes the refractive index of the SSB optical modulation section 20 so that the unnecessary sideband component of the optical intensity-modulated signal outputted from the SSB optical modulation section 20 disappears.

Abstract: An optical modulation apparatus that performs optimum bias voltage control for optical modulation without using a pilot tone. A drive unit generates a drive signal by adding a bias voltage to an input data signal. A light modulation unit modulates input light output from a light source unit, in accordance with the drive signal, and outputs the results as optical signals. A forward monitoring unit monitors a forward signal of the light modulation unit and outputs the forward signal. A reverse monitoring unit monitors a reverse signal of the light modulation unit and outputs a reverse signal. A bias control unit controls the bias voltage so that a measured monitor ratio matches a target value of the ratio between the forward signal and the reverse signal, obtained when the operating point of the light modulation unit is in a predetermined position on its operation characteristic curve.

Abstract: Provided is a method for using a display system. The method, in one embodiment, includes directing a light beam from a light source to an array of individually addressable pixels of a spatial light modulator. The method further includes modulating the light beam into a first portion of light using a first addressable pixel, and a second portion of light using a second addressable pixel. Thereafter, the method includes directing the first portion of light having a first incident angle and the second portion of light having a second different incident angle toward an angle-selective retro-reflector, the angle-selective retro-reflector configured to transmit the first portion of light onto a display target, and reflect the second portion of light back toward the second addressable pixel. Additionally, the method includes recycling the reflected second portion of light to the pixels of the spatial light modulator.

Abstract: A bias controller and a method for controlling the bias of an electro-optic modulator are provided. In the method, for a received indication of modulator temperature, steps are provided for accessing a look-up table to determine a corresponding value of bias voltage, for a required bias point, to apply to the modulator. If no such value is stored, additional steps are provided to generate a pilot tone for input to the modulator and to recognize, from the signal content of a modulated optical signal output by the modulator, operation of the modulator at the required bias point, adjusting the value of bias voltage being applied to the modulator as required. When operation at the required bias point is recognized, the respective value of bias voltage for that modulator temperature is stored in the look-up table. The same method is provided to configure a bias controller in respect of a given modulator, if necessary ab initio.

Abstract: A system and method for locking the relative phase of multiple coherent optical signals, which compensates for optical phase changes induced by vibration or thermal changes in the environment.

Abstract: A driving apparatus supplies a drive signal to an optical modulator corresponding to a phase modulation format, and also, divides a part of an output light from the optical modulator; extracts some optical component of the divided light, which is distant from a carrier frequency by integral multiple of a modulation frequency, to detect a power of the optical component; and feedback controls a duty ratio of the drive signal or a cross-point level thereof so that the detected power approaches a minimum value. Thus, it is possible to stably perform phase modulation with high precision.

Abstract: The present invention relates to a bias controller for a dual output electro-optic modulator and a method for controlling the bias of a dual output electro-optic modulator. The invention further comprises an optical commutator switch with a plurality of dual-output electro-optic modulators interconnected in a tiered arrangement, and control means for deriving measurements of optical power from each of the modulators. The optical commutator is further used for determining respective bias control signals to achieve and maintain operation of the modulators substantially at their quadrature bias points, and further for generating said respective bias control signals for applying them to the respective modulators.

Abstract: Examples and implementations of photonic devices and techniques based on whispering gallery mode resonators formed of electro-optic materials to effectuate cross modulation between whispering gallery modes of different polarizations in the resonators.

Abstract: A system and method for providing a wavefront corrected high-energy beam of electromagnetic energy. In the illustrative embodiment, the system includes a source of a first beam of electromagnetic energy; an amplifier for amplifying said beam to provide a second beam; a sensor for sensing aberration in said second beam and providing an error signal in response thereto; a processor for processing said error signal and providing a correction signal in response thereto; and a spatial light modulator responsive to said correction signal for adjusting said beam to facilitate a correction of said aberration thereof. In more specific embodiments, the source is a laser and the sensor is a laser wavefront sensor. A mirror is disposed between said modulator and said sensor for sampling said beam. The mirror has an optical thin-film dielectric coating on at least one optical surface thereof. The coating is effective to sample said beam and transmit a low power sample thereof to said means for sensing aberration.

Abstract: Lighting systems comprising a spectrum former upstream from a reflective pixelated spatial light modulator (reflective SLM), the SLM reflecting substantially all of the light in the spectrum into at least two different light paths, that do not reflect back to the light source or the spectrum former. At least one of the light paths acts as a projection light path and transmits desired light out of the lighting system. The lighting systems provide virtually any desired color(s) and intensity(s) of light, and avoid overheating problems by deflecting unwanted light and other electromagnetic radiation out of the system or to a heat management system. The systems can be part of another system, a luminaire, or any other suitable light source. The systems can provide virtually any desired light, from the light seen at the break of morning to specialized light for treating cancer or psoriasis, and may change color and intensity at speeds that are perceptually instantaneous.

Abstract: A Mach-Zehnder (MZ) interferometer modulator structure for fiberoptic telecommunications is disclosed in which drift of the operating point can be monitored with a reduced phase tracking error. One or more components of free-space light radiated into the substrate of the MZ modulator are selectively detected with one or more photodetectors. Suitable summing circuits are described for nulling out undesired photocurrent contributions in the photodetector(s) from on-state and off-state light radiated from the MZ.

Abstract: A signal processing device includes: a phase controller configured to control respective phases of an in-phase signal and an quadrature signal, which are obtained by converting an analog signal into a digital signal when a multi-value phase modulation light is demodulated, by digital signal processing; and a control amount provider configured to provide a control amount to the phase controller based on an output of the phase controller.

Abstract: According to an aspect of an embodiment, an optical modulation device includes a Mach-Zehnder modulator and a controller. The Mach-Zehnder modulator is supplied a drive signal and a bias voltage. The Mach-Zehnder modulator modulates inputted light on the bases of the drive signal and the bias voltage. The drive signal selectively is superimposes a predetermined frequency signal. The bias voltage selectively is superimposes the predetermined frequency signal. The controller selects a superimposing target which is the drive signal or the bias voltage so as to change modulation formats.

Abstract: An optical switching apparatus changes an angle of a movable mirror reflecting light input to the optical switching apparatus and performs switching control for switching an output port that outputs the light reflected by the movable mirror. The optical switching apparatus includes an acquiring unit that acquires intensity information concerning the light output from the output port; a controller that based on the intensity information acquired by the acquiring unit and by adjusting the angle of the movable mirror, performs intensity control of the light output; a detector that based on the intensity information, detects a fluctuation greater than a predetermined fluctuation amount of the light output; and a suspending unit that suspends the intensity control by the controller, if the detector detects the fluctuation.

Abstract: The present invention purposes to provide a THz-wave generator capable of generating a THz-wave stably and efficiently, and particularly, to provide the THz-wave generator which is stable against a frequency shift of a laser source and which can easily vary the frequency of the THz-wave. A THz-wave generator, for inputting a laser beam from a light source unit A including a laser source to a THz-wave generating element D, and generating a THz-wave (fT) from the THz-wave generating element, wherein a light circulating unit including an SSB optical modulator, and wavelength selecting means C are disposed between the laser source A and the THz-wave generating element D, the laser beam is guided into the light circulating unit, a specific wavelength lightwave is selected out of lightwaves having a plurality of wavelengths generated in the light circulating unit by the wavelength selecting means, and the specific wavelength (f0, fn) lightwave is input to the THz-wave generating element.

Abstract: A control apparatus for an external modulator that modulates light emitted from a light source based on an input signal, the control apparatus comprises: a low-frequency signal generating device that generates and outputs a low-frequency signal having a predetermined frequency; a signal superimposing device that superimposes a first modulation signal, which is the input signal on the low-frequency signal, to make a second modulation signal, and applies this second modulation signal to the external modulator; a low-frequency signal detecting device that detects the low-frequency signal component from an optical output of the external modulator, compares a phase of this detected low-frequency signal with a phase of a low-frequency signal output from the low-frequency signal generating device, and outputs a signal according to a phase difference; an operating point control device that controls based on an output signal of the low-frequency signal detecting device, so as to compensate for operating point drift of

Abstract: The present invention provides systems and methods for chirp control of a dual arm Z-modulator to minimize dispersion in the fiber plant. The chirp control is based upon a real-time control loop based upon performance monitoring data between a transmitter and a receiver. Advantageously, the present invention enables improved performance in high-speed optical systems, and in some cases can eliminate or minimize the need for external dispersion compensation fiber (DCF).

Abstract: DQPSK modulator control is provided using a single monitor photodiode with a selectively injected dither tone. The dither tone signal is sequentially injected into arm modulators and/or to a modulator driver port in time slots. A tapped signal at the output of the modulator is monitored synchronously with injected dither (I arm, Q arm, or phase modulator in third slot). The recovered dither output from a single photodiode is processed in the same sequence as the dither injection to adjust the bias to the optimal point: I-arm at the null point, Q-arm at the null point, and phase modulator at the quadrature point. This technique can be used for any control where the rate of change of the monitored condition due to systemic or environmental conditions (e.g., temperature, aging, etc.) is slow enough to allow time slot dither injection, monitor, and control.

Abstract: A high-speed optical amplifier is considered to be an important optical device because of an increasing demand of routing, which is accompanied by an increase in complexity of networks. It is difficult to satisfy a response performance by related-art techniques, and there has been a problem in achieving a high-speed response performance of 10 microseconds or less. An optical amplifier according to the present invention includes: an input monitor means 500; an optical amplification means 310 including an optical amplification medium 300, and a control means 400 for performing feed-forward control. When the optical amplification means is controlled by the feed-forward control in response to a signal of the input monitor means 500, an overshoot signal is applied as a control signal so that a slow response performance specific to the optical amplification medium has been improved, and thereby high-speed response performance has been achieved.

Abstract: An integrated control system for a laser and Mach-Zehnder interferometer are disclosed and may include configuring a bias point for low-speed control of an optical modulator utilizing control circuitry integrated on the same CMOS die. The optical modulator may be differentially monitored. A laser source for the modulator may be controlled utilizing monitor photodiodes via optical taps on outputs of the modulator, or utilizing a monitor photodiode on one output port of the modulator, which may comprise a Mach-Zehnder interferometer. An error signal may be generated by subtracting monitor photodiode signals from optical taps on output ports of the modulator. The bias point of the modulator may be adjusted by minimizing the error signal. Calibration time of the bias point may be reduced utilizing electronic data inversion. An output of the modulator may comprise a Y-junction and a single monitor photodiode may measure both branches of the modulator.

Abstract: A waveform controller includes a monitor configured to monitor a waveform of an output pulse obtained by the response of a responsive element to a driving signal supplied thereto and a driving waveform shaper configured to shape a waveform of the driving signal based on a monitoring result obtained by the monitor.

Abstract: The present invention relates generally to a methodology of maintaining correlated colour temperature (CCT) of light beam from lighting means by having a processing means to instruct several lighting means groups, wherein each group has different CCT ranges, that are arranged together, to provide light beam of intended CCT, if the CCT of light beam from the lighting means that are reflected back using reflecting means, which are captured and converted to binary data by the sensory means are different from the intended CCT.

Abstract: Photonic devices and techniques based on tunable single sideband (SSB) modulation in whispering gallery mode resonators formed of electro-optic materials to effectuate coupling between whispering gallery modes of different polarizations.

Abstract: A lighting system operating using a digital mirror as its operative device. The digital mirror is used to shape the light which is a passed through advanced optical devices in order to produce an output.

Abstract: In each light modulator element of a special light modulator with diffraction grating structure where moving ribbons and fixed ribbons are alternately arranged, the maximum light-amount (I1) when an output light-amount first becomes maximum from when the moving ribbons start to sag and the maximum light amount-voltage becoming an displacement amount (P1) at the maximum light-amount, are obtained and the minimum of a plurality of maximum light-amounts is set as a target ON light-amount (It). Since a voltage (corresponding to a displacement amount (Pt1)) between the maximum light amount-voltage and the minimum light amount-voltage at a displacement amount (P2) is obtained as a target ON-voltage for the target ON light-amount (It), it is thereby possible to prevent moving distance of the moving ribbons among ON/OFF from largely differing among the light modulator elements and achieve an appropriate image recording.

Abstract: The invention relates to a device for regenerating the phase of an optically modulated signal with phase changes and based on two and three replicas, wherein the replicas refer to the number of identical signals that are obtained form the input signal. This regenerator is capable of regenerating the phase and period of any format of modulation of optical communications systems which are differential modulation with phase changes, such as: DISK, DQPSK, RZ-DQPSK, RZ-DQPSK, D8PSK, D8PSK, RZ-D16PSK, D16PSK. The regenerator design presented involves the regenerator being placed alter the multiplexer of a communications system and before the signal modulators and/or decoders. Thus the regenerator receives the signal leaving the multiplexer and this signal is input in an amplitude modulator.

Abstract: Provided is a method for using a display system. The method, in one embodiment, includes directing a light beam from a light source to an array of individually addressable pixels of a spatial light modulator. The method further includes modulating the light beam into a first portion of light using a first addressable pixel, and a second portion of light using a second addressable pixel. Thereafter, the method includes directing the first portion of light having a first incident angle and the second portion of light having a second different incident angle toward an angle-selective retro-reflector, the angle-selective retro-reflector configured to transmit the first portion of light onto a display target, and reflect the second portion of light back toward the second addressable pixel. Additionally, the method includes recycling the reflected second portion of light to the pixels of the spatial light modulator.

Abstract: In a light modulating apparatus of an external modulating type which is used in an optical communication system, there are provided an LN modulator, a light branching circuit, a photoelectric converter, a bias control circuit, a driver for an LN modulator which serves to drive the LN modulator in response to an input electric signal, a capacitor for cutting off DC and low frequency components of the input electric signal, a low frequency component compensating circuit for compensating the DC and low frequency components of the input electric signal, and an adding circuit for adding an output of the bias control circuit and that of the low frequency component compensating circuit and generating a bias control signal of the LN modulator.

Abstract: An optical transmitter includes: a modulating unit that modulates an optical signal based on an electric signal; a first detecting unit that detects a first variation width of a maximum output of the modulated optical signal; a second detecting unit that detects a second variation width of a minimum output of the modulated optical signal; a comparing unit that performs a comparison of the first variation width and the second variation width; and an adjusting unit that adjusts a bias potential of the electric signal based on a result of the comparison.

Abstract: Whispering-gallery-mode (WGM) optical resonators made of crystal materials to achieve high quality factors at or above 1010.

Abstract: A method of piloting an optical polarization controller including a cascade of variable polarization transformers that can be driven individually to realize overall a polarization transformation between an input optical signal and an output optical signal with each transformer having predetermined maximum and minimum end driving limits. For each transformer the method includes cyclically the steps of finding an error signal output to the controller and driving a first transformer polarization variation by a predetermined amount CS in one of the two directions to check whether with this variation the error signal is reduced and, if not, driving in the opposite direction. The decision of which of the two directions to drive first is made each time and is not fixed. Equipment in accordance with the method is also described.

Abstract: A system and method for generating an optical return-to-zero signal with frequency chirp. The system includes a bit separator configured to receive an electrical non-return-to-zero signal and generate a first input signal and a second input signal. Additionally, the system includes a first driver configured to receive the first input signal and generate a first driving signal. The first driving signal is proportional to the first input signal in signal strength. Moreover, the system includes a second driver configured to receive the second input signal and generate a second driving signal. The second driving signal is proportional to the second input signal in signal strength. Also, the system includes a light source configured to generate a light, and an electro-optical modulator.

Abstract: A method of controlling the operating parameters of an optical modulator, without using a dither signal, is provided. Past operating parameters are compared to present operating parameters using a quality of modulation signal obtained by cross-correlating the data modulation signal used to drive the optical modulator with the modulated optical signal output from the optical modulator. The quality of modulation signal is used to optimize the operating parameters (e.g., bias point) of the optical modulator, or other operating parameters of the arrangement, such as the modulator drive level, timing alignment, etc.

Abstract: Lighting systems comprising a spectrum former upstream from a reflective pixelated spatial light modulator (reflective SLM), the SLM reflecting substantially all of the light in the spectrum into at least two different light paths, that do not reflect back to the light source or the spectrum former. At least one of the light paths acts as a projection light path and transmits desired light out of the lighting system. The lighting systems provide virtually any desired color(s) and intensity(s) of light, and avoid overheating problems by deflecting unwanted light and other electromagnetic radiation out of the system or to a heat management system. The systems can be part of another system, a luminaire, or any other suitable light source. The systems can provide virtually any desired light, from the light seen at the break of morning to specialized light for treating cancer or psoriasis, and may change color and intensity at speeds that are perceptually instantaneous.

Abstract: A feedback system and method for controlling TE/TM power ratio of light source is proposed. A specially-designed mark is positioned on the mask. The mark and the mask are illuminated by incident light emanated from the light source, and the reflected light or the refracted light of the incident light is detected to provide an output signal. Then, the signal is input into a polarization converter. In this way, the TE/TM polarization power ratio of the light source can be controlled.

Abstract: In an optical amplifier according to the present invention, a change signal from a change signal source is fed into a light source or a drive circuit. The wavelength of light outputted from the light source is changed based on the change signal. The wavelength-changed output light from the light source is outputted as pumping light from a pumping light generator to be supplied backwardly via an optical multiplexer/demultiplexer into an optical fiber. Signal light is Raman-amplified in the optical fiber with the supply of the pumping light.