Abstract: A device for a presence detection system for detecting the presence of a user close to a motor vehicle is configured to: activate a piezoelectric element during an “awake” time interval to stabilize the piezoelectric element; then, control the supply of voltage to an oscillator and supply the oscillator with a reference electrical signal forming a current voltage reference, so the transceiver circuit transmits a signal during what is called a “transmission” time interval; during the transmission time interval, measure the frequency of a reflected signal resulting from the transmitted signal, measure the frequency of the transmitted signal, and determine a corrected reference based on the measured frequency of the transmitted signal, allowing the oscillator to operate at a target frequency value. This allows limiting the energy consumption of a transceiver device used to detect the presence of a user close to a motor vehicle.

Abstract: An objective is to provide an acoustic mode propagation speed measurement method and an acoustic mode propagation speed measurement device capable of measuring a propagation speed of an acoustic mode without cutting or processing an optical fiber wire. According to the present invention, an acoustic mode propagation speed measurement method includes: acquiring a frequency shift spectrum of Brillouin scattered light generated in an optical fiber; fitting the frequency shift spectrum using a Gauss function; acquiring a spectral full-width at half maximum w from a fitted curve using the Gauss function; and calculating a propagation speed VA of an acoustic mode of the optical fiber by substituting the acquired spectral full-width at half maximum w into a linear function of the spectral full-width at half maximum w and the propagation speed VA of the acoustic mode.

Abstract: Optical apparatus includes an acousto-optic medium and an array of multiple piezoelectric transducers attached to the acousto-optic medium. A drive circuit is coupled to apply to the piezoelectric transducers respective drive signals including at least first and second frequency components at different, respective first and second frequencies and with different, respective phase offsets for the first and second frequency components at each of the multiple piezoelectric transducers.

Abstract: A sampling circuit includes: a phase synchronization circuit for generating, by a phase-locked loop, an N-multiplied clock that is N times as high as the scanning frequency of a scanning position signal of a resonant scanner and is synchronized with the phase of the scanning position signal, an AD converter for AD-converting a detection signal obtained by detecting light from a sample in synchronization with the N-multiplied clock, a counter for counting the number of clocks in synchronization with the N-multiplied clock, a memory for storing a counter threshold corresponding to a desired scanning position of the resonant scanner, a comparison circuit for outputting a sampling clock in response to the counter threshold and a counter value of the counter circuit coinciding with each other, and a data processing circuit for sampling the AD-converted detection signal based on the sampling clock and generating pixel data.

Abstract: A photographic light generating panel includes, in some examples, front and rear support rings that are selectively foldable from an open position with a circular shape to a coiled position in which the front and rear support rings are each coiled into two or more loops. The light generating panel also includes a flexible rear panel having an outer edge that is coupled along a periphery of the rear support ring, a flexible front panel having an outer edge that is coupled along a periphery of the front support ring, an optional annular covering fabric layer coupled between the periphery of the front support ring and the periphery of the rear support ring, and multiple light emitting diodes (LEDs) between the front and rear panels. Light from the LEDs reflects off the rear panel toward the front panel, which disperses the light.

Abstract: Direct signal distribution at mm-wave frequencies is provided by using dielectric waveguides for passive coherent distribution. The relevant distribution path lengths at mm-wave frequencies are short enough that accumulated phase error is not a significant problem. Meanwhile, the dielectric waveguides provide low loss and substantial immunity to electrical interference, thereby avoiding the main disadvantages of direct signal distribution in RF systems.

Abstract: An imaging system includes a diffusing element configured to couple portions of a light beam back into a laser diode. The system includes a diode laser driven into a chaotic regime by a combination of a diffuser and a modulated drive current such that it emits light across a frequency spectrum having an envelope between 3 and 10 nanometers wide. The system further includes a diffusing element at least 0.1 mm to 0.5 mm away from the diode laser to couple portions of the light beam back into the laser diode. Another embodiment is directed to using the diffusing element to illuminate a flat panel display or a spatial light modulator.

Abstract: Disclosed is an illumination device for an apparatus for establishing the color of a tooth, including in the mouth, the illumination device including a support with a lens system that includes at least one lens, an illumination unit, image capturing unit, and a front protection. The illumination unit is arranged at the periphery of the visual field of the lens system.

Abstract: Briefly, in accordance with one or more embodiments, a MEMS laser beam display to implement mixed-mode depth detection comprises an imaging engine to project an image in a field of view of the MEMS laser beam display, a time of flight (TOF) depth detector to determine a distance to a target within the field of view in a first mode of depth detection, wherein the TOF depth detector determines coarse depth data of the target, and a structured light depth detector to determine a distance to the target in a second mode of depth detection, wherein the structured light depth detector determines fine depth data of the target. Depth processing circuitry may generate a composite three-dimensional (3D) image of the target, or may identify a gesture region of the target for gesture recognition.

Abstract: Systems, methods, and apparatus, including non-transitory computer-readable storage medium, for amplifying pulsed laser radiation in an EUV laser driver are provided. An example EUV laser driver includes a beam source configured to produce the pulsed laser radiation with at least one laser frequency, an amplifier arrangement with at least one optical amplifier for amplifying the pulsed laser radiation, the at least one optical amplifier having a frequency-dependent gain with a maximum gain at a maximum frequency, at least one frequency shifter configured to produce a frequency shift for the laser frequency of the pulsed laser radiation relative to the maximum frequency, and a controller configured to set the frequency shift such that a gain of the at least one optical amplifier for the pulsed laser radiation is reduced to less than a percentage, e.g., 90%, 70%, or 50%, of the maximum gain.

Abstract: Disclosed is an optical fiber arrangement for inducing coupling among propagation modes of light, said arrangement comprising a multimode optical fiber (30) having an input end (32) for receiving light and an output end (31) for emitting light, with a coupling inducing section (33) extending from said input end to said output end, and a holder (80) on which the optical fiber is arranged, wherein said multimode optical fiber has a non-circular cross section. Disclosed also is a system for measuring the absorption or determining the concentration of a substance, said system comprising at least one optical fiber arrangement.

Abstract: Systems, methods, and apparatus, including non-transitory computer-readable storage medium, for amplifying pulsed laser radiation in an EUV laser driver are provided. An example EUV laser driver includes a beam source configured to produce the pulsed laser radiation with at least one laser frequency, an amplifier arrangement with at least one optical amplifier for amplifying the pulsed laser radiation, the at least one optical amplifier having a frequency-dependent gain with a maximum gain at a maximum frequency, at least one frequency shifter configured to produce a frequency shift for the laser frequency of the pulsed laser radiation relative to the maximum frequency, and a controller configured to set the frequency shift such that a gain of the at least one optical amplifier for the pulsed laser radiation is reduced to less than a percentage, e.g., 90%, 70%, or 50%, of the maximum gain.

Abstract: The invention relates to a scanner for an oral cavity comprising: an optical output unit for outputting a line laser beam; a first optical system for reflecting the line laser beam output from the optical output unit to a scanning target tooth; an optical sensing unit for sensing the line laser beam reflected again by the first optical system after reflected from the scanning target tooth; and a control unit for controlling operations of the optical output unit and the first optical system. The control unit controls the reflection angle and position of the first optical system.

Abstract: An actuation device for a laser diode includes: a first driver device which is set up to generate a high-frequency modulated actuation signal and to feed the signal into the laser diode for speckle suppression, and an evaluation circuit, which is coupled with the first driver device, and which is set up to output to the first driver device an intensity signal indicating the intensity of the light emitted by the laser diode and a control signal as a function of the intensity signal in order to regulate the high-frequency modulated actuation signal.

Abstract: The invention concerns an oscillator generating a wave composed of a frequency of on the order of terahertz from a beat of two optical waves generated by a dual-frequency optical source. The oscillator includes a modulator the transfer function of which is non-linear for generating harmonics with a frequency of less than one terahertz for each of the optical waves generated by the dual-frequency optical source, an optical detector able to detect at least one harmonic for each of the optical waves generated by the dual-frequency optical source and transforming the harmonics detected into an electrical signal, a phase comparator for comparing the electrical signal with a reference electrical signal, and a module for controlling at least one element of the dual-frequency optical source with a signal obtained from the signal resulting from the comparison.

Abstract: In an optical modulation device, a first drive signal and a first bias signal are applied to a phase modulation unit, a second drive signal and a second bias signal are applied to a phase modulation unit, and a third bias signal is applied to a ?/2 phase shift unit. A control unit adjusts the third bias signal in a first adjustment period, adjusts the first drive signal and the first bias signal in a second adjustment period next to the first adjustment period, and adjusts the second drive signal and the second bias signal in a third adjustment period next to the second adjustment period. The control unit starts the second adjustment period before a gap between the current value of an adjustment reference signal and a target value is filled, and starts the third adjustment period before a gap in the second adjustment period is filled.

Abstract: The invention relates to an external cavity tunable laser. The laser comprises an extracavity collimating lens arranged outside a laser cavity, and a laser output mirror, a laser gain medium, an intracavity collimating lens, an active optical phase modulator and a tunable optical filter all arranged sequentially inside the laser cavity. The laser further comprises an active polarization rotator arranged behind the tunable optical filter, a polarization beam splitter arranged behind the active polarization rotator, a first etalon and a first total reflection mirror arranged in the direction vertical to the optic axis of a laser cavity output lens, a second etalon and a second total reflection mirror arranged in the direction of the optic axis of the laser cavity output lens, and a laser drive and control circuit.

Abstract: A tunable laser, including: a laser resonant cavity; a laser gain medium; an intra-cavity collimating lens; an acousto-optic tunable filter; a device exciting sound waves in an acousto-optic crystal; a radio frequency signal source providing radio frequency energy for the energy transducer and adjusting the oscillation wavelength of the laser resonant cavity by changing radio signal frequency; an optical phase modulator disposed between the intra-cavity collimating lens and the acousto-optic crystal; an optical etalon disposed between the optical phase modulator and the laser gain medium; a wavelength locker disposed at one of zero-order diffraction optical paths of intra-cavity light; a pigtailed collimator coupling laser output light to an optical fiber; a pumping source exciting the laser gain medium; a phase modulator driver for driving the optical phase modulator; and a signal control processing circuit.

Abstract: An acousto-optical filter element (114) is provided which has an acousto-optical crystal (118) having an acoustic signal transmitter (120) for generating acoustic signals in the acousto-optical crystal (118). The acousto-optical crystal (118) is designed to selectively spatially deflect light of a target wavelength from an input light beam (116) entering into the acousto-optical crystal (118), as a function of a high frequency applied to the acoustic signal transmitter (120), and to thereby produce a target light beam (126) having the target wavelength. In addition, the acousto-optical filter element (114) includes a spatial filter element (132) which is located in the target light beam (126) and is designed to selectively suppress the intensity of the target light beam (126) in a plane perpendicular to the propagation direction of the target light beam (126).

Abstract: An acousto-optic (AO) device includes an AO interaction crystal for receiving and propagating a light ray along an optical propagation direction (OPD). A piezoelectric transducer is on at least one surface of the AO interaction crystal for receiving an electrical signal and emitting an acoustic wave into the AO interaction crystal. An electrode is on the piezoelectric transducer for coupling the electrical signal to the piezoelectric transducer. The electrode is a patterned electrode that includes a plurality of different transverse edge positions. The plurality of different transverse edge positions span a position range of at least five percent of an average height (Havg) of the electrode.

Abstract: An acousto-optical filter element (114) is provided which has an acousto-optical crystal (118) having an acoustic signal transmitter (120) for generating acoustic signals in the acousto-optical crystal (118). The acousto-optical crystal (118) is designed to selectively spatially deflect light of a target wavelength from an input light beam (116) entering into the acousto-optical crystal (118), as a function of a high frequency applied to the acoustic signal transmitter (120), and to thereby produce a target light beam (126) having the target wavelength. In addition, the acousto-optical filter element (114) includes a spatial filter element (132) which is located in the target light beam (126) and is designed to selectively suppress the intensity of the target light beam (126) in a plane perpendicular to the propagation direction of the target light beam (126).

Abstract: A color tunable substrate is disclosed. The color tunable substrate includes multiple layers. A color of the color tunable substrate can be tuned by altering or adjusting characteristics of the layers included in the color tunable substrate.

Abstract: Systems and methods for mitigating multipath signals in a receiver are provided. In this regard, a representative system, among others, includes a radio frequency (RF) front-end and at least one analog-to-digital converter (ADC). The RF front-end receives FM signals and down-converts the received frequency signals to intermediate frequency (IF) signals. The analog-to-digital converter (ADC) receives the intermediate frequency signals and digitizes multiple FM channels around a desired FM channel associated with the down-converted signals. The system further includes multiple sets of digital processing components that are configured to simultaneously receive and process the digitized multiple channels. The multiple sets of digital processing components include at least two parallel channel selection and demodulation paths in which the respective digitized multiple channels are processed therethrough.

Abstract: An optical combination includes an input lens having an optical axis for receiving incoming rays, an output Petzval lens combination including spaced apart doublet lenses L3 and L4 both aligned along the optical axis, and an acousto-optic tunable filter (AOTF) that defines an input side and an output side for the optical combination positioned between the input lens and L3. An input aperture stop is on the input side and an output beam stop is on or near L4. The input lens can be an input Petzval lens combination including spaced apart doublet lenses L2 and L1, wherein the input aperture stop is on or near L2, and the input Petzval lens combination and output Petzval lens combinations are aligned back-to-back.

Abstract: A wavefront modification apparatus that has a plurality of acoustic emitters, the acoustic emitters configured to emit acoustic waves which travel at least partially across a radiation beam conduit. The acoustic emitters may be configured to establish a standing acoustic wave which extends at least partially across the radiation beam conduit. The wavefront modification apparatus may be provided in a lithographic apparatus, and may be used to modify the wavefront of a radiation beam which is used by the lithographic apparatus to project a pattern onto a substrate.

Abstract: A beam adjuster assembly (14) receives an input beam (16) and provides a first output beam (18) and a spaced apart second output beam (20). The beam adjuster assembly (14) comprises a first frequency adjuster (22) and a second frequency adjuster (24). The first frequency adjuster (22) receives the input beam (16). The first frequency adjuster (22) transmits a first portion of the input beam (16) to provide the first output beam (18) having a first output frequency. Additionally, the first frequency adjuster (22) adjusts a second portion of the input beam (16) to provide a first adjusted beam (354). The second frequency adjuster (24) receives the first adjusted beam (354). Moreover, the second frequency adjuster (24) adjusts at least a portion of the first adjusted beam (354) to provide the second output beam (20) having a second output frequency that is different than the first output frequency.

Abstract: A method for irradiating a medium includes irradiating the medium with an electromagnetic wave which is scattered in the medium and modulated in frequency at a position in the medium; obtaining information corresponding to an interference pattern generated by interference between the modulated electromagnetic wave and a reference wave; and generating a phase conjugate wave, based on the obtained information, which irradiates the medium.

Abstract: An optical combination includes an input lens having an optical axis for receiving incoming rays, an output Petzval lens combination including spaced apart doublet lenses L3 and L4 both aligned along the optical axis, and an acousto-optic tunable filter (AOTF) that defines an input side and an output side for the optical combination positioned between the input lens and L3. An input aperture stop is on the input side and an output beam stop is on or near L4. The input lens can be an input Petzval lens combination including spaced apart doublet lenses L2 and L1, wherein the input aperture stop is on or near L2, and the input Petzval lens combination and output Petzval lens combinations are aligned back-to-back.

Abstract: A laser apparatus includes a laser capable of generating a laser signal; structure for conditioning the laser signal; and structure for varying the beamwidth of the laser signal as it is scanned into the field of view.

Abstract: An acousto-optical filter element (114) is provided which has an acousto-optical crystal (118) having an acoustic signal transmitter (120) for generating acoustic signals in the acousto-optical crystal (118). The acousto-optical crystal (118) is designed to selectively spatially deflect light of a target wavelength from an input light beam (116) entering into the acousto-optical crystal (118), as a function of a high frequency applied to the acoustic signal transmitter (120), and to thereby produce a target light beam (126) having the target wavelength. In addition, the acousto-optical filter element (114) includes a spatial filter element (132) which is located in the target light beam (126) and is designed to selectively suppress the intensity of the target light beam (126) in a plane perpendicular to the propagation direction of the target light beam (126).

Abstract: An acousto-optical system is described comprising at least one acousto-optical element having at least one transducer that is attached to a crystal, a driver unit for generating at least one acoustic signal for driving acousto-optical elements modifying light transmitted through the acousto-optical element and comprising at least one digital data processing unit, at least one digital-to-analog converter transforming the digital combination signal into an initial analog driver signal, and an amplifier for amplifying the initial analog driver signal to become said analog electronic driver signal. Further, a microscope and a method of operating the acousto-optical element is are described. Various objectives are achieved like more flexibility, real time compensation for non-linearity and reducing the number, size, costs and energy consumption of electronic components.

Abstract: The refractive index of the at least one photonic structure having two separate photonic bands is modulated, so that light supplied to the at least one photonic structure and initially in one of the two photonic bands of the traveling along a forward direction in the at least one photonic structure is converted to light in a second one of the photonic bands, and light in the one photonic band traveling along a backward direction opposite to the forward direction in the at least one photonic structure is not converted and remains in the one photonic band, achieving non-reciprocity. An interferometer comprises a first and a second photonic structure coupled at two coupler regions. The first photonic structure has two separate photonic bands.

Abstract: An active optical filter transmits or blocks light according to whether or not a magnetic field is applied, and functions as an optical filter transmitting light having a predetermined wavelength when light is transmitted according to a magnetic field. The active optical filter includes: an optical filter layer for transmitting or blocking light according to whether or not a magnetic field is applied; and a magnetic field applying unit surrounding the optical filter layer for applying a magnetic field to the optical filter layer. The optical filter layer has a multi-layer thin layer structure which is formed of two kinds of thin layers having different respective refractive indices and sequentially and periodically stacked on a substrate.

Abstract: An acousto-optical filter element (114) is provided which has an acousto-optical crystal (118) having an acoustic signal transmitter (120) for generating acoustic signals in the acousto-optical crystal (118). The acousto-optical crystal (118) is designed to selectively spatially deflect light of a target wavelength from an input light beam (116) entering into the acousto-optical crystal (118), as a function of a high frequency applied to the acoustic signal transmitter (120), and to thereby produce a target light beam (126) having the target wavelength. In addition, the acousto-optical filter element (114) includes a spatial filter element (132) which is located in the target light beam (126) and is designed to selectively suppress the intensity of the target light beam (126) in a plane perpendicular to the propagation direction of the target light beam (126).

Abstract: Devices for modulating light signals. A modulator includes a rolled optical fiber cable having a preset tensile stress along the longitudinal axis thereof, a coating layer applied to the rolled optical cable, and at least one piezo acoustic transducer secured to the coating layer. The piezo acoustic transducer is operative to generate a sound wave that modulates a frequency of a light signal passing through the rolled optical fiber cable.

Abstract: An optical module is configured with a combination of a single-mode oscillating light source and an optical filter. In this optical module, the single-mode oscillating light source outputs a single-mode, frequency-modulated signal. Further, the optical filter converts the frequency modulation to an amplitude modulation. And, the single-mode oscillating light source and the optical filter are packaged without active alignment on the same substrate. Accordingly, it is possible to realize an optical module in a simple and low-cost configuration by packaging the single-mode oscillating light source and the optical filter by passive alignment, without active alignment, on the same substrate, and by using a simple optical filter such as a waveguide ring resonator, which converts a frequency modulation to an amplitude modulation.

Abstract: The inventive method for opto-acoustical imagery of an image object consists in a) generating an incident optical wave and a reference optical wave coherent therewith, b) oscillating the image object area at an acoustic frequency, c) sending the incident wave to said image object, thereby generating a diffused signal wave, d) sending at least one part of said diffused signal wave to a detection device, e) sending the reference optical wave to the detection device avoiding the image object, thereby generating an interferogram I (r, t), f) extracting digital information from said interferogram I (r, t), and in g) obtaining co-ordinates from one measurement point of the image object associated to said digital information.

Abstract: A scanning system is disclosed including a hand-held scanning device for capturing three-dimensional information of an object. The scanner system includes a high-speed transceiver having a high-speed laser light source, a high frequency MEMS oscillating scanning mirror and software for frame registration. Laser based range finding technique is used to map the scanned object. MEMS oscillating at high speed enables rapid and accurate scanning of an object. The scanning can be performed without knowledge or even precise control of the position of the object relative to the scanner. Random movement of the object during scanning is also possible. The scanner can be used for a variety of purposes, including medical and industrial purposes. The illustrated embodiment is in-vivo scanning of human teeth for purposes of orthodontic treatment planning and diagnosis.

Abstract: This application describes designs, implementations, and techniques for controlling propagation mode or modes of light in a common optical path, which may include one or more waveguides, to sense a sample.

Abstract: A resonance system (14, 15) is formed by a light incident side reflection mirror and a light exiting side reflecting mirror, arranged parallel to each other. The light incident on an incident side reflective mirror (14) is propagated in the outward path direction or in the backward path direction so that the light is set in a resonant state. The light in the resonant state in the resonance system (14, 15) is phase-modulated, responsive to a modulating signal supplied from an oscillating device (16) by a light modulation device (2) arranged between the light incident side reflective mirror (14) and the light exiting side reflective mirror (15). The oscillating device oscillates the modulating signal of a frequency fm.

Abstract: A portable acousto-optical (AO) spectrometer system comprised of at least one AO crystal cell device specially designed for cancellation of side-lobe noise at a desired tuned wavelength of operation. Each AO crystal cell device has a transducer attached and forms an AO tunable filter (AOTF) and forms part of a photo-head assembly. The system can include an optical fiber link between the AO spectrometer photo-head assembly and additional features such as an optical alignment coupling attachment that couple an excitation source such as a laser that operates in either pulse or continuous mode, a probing fiber that provides a hand-held member that can emit a source radiation and in turn observe radiation reflected from an observed sample. There are two embodiment of the AO crystal cell device. Either embodiment of the AO crystal cell design can be used in the system, providing a vibration-insensitive AO spectrometer instrument having high sensitivity, accuracy and resolution capabilities.

Abstract: Devices for modulating light signals. A modulator includes a rolled optical fiber cable having a preset tensile stress along the longitudinal axis thereof, a coating layer applied to the rolled optical cable, and at least one piezo acoustic transducer secured to the coating layer. The piezo acoustic transducer is operative to generate a sound wave that modulates a frequency of a light signal passing through the rolled optical fiber cable.

Abstract: Techniques for producing an optical broadband frequency sweep or chirp, include generating a narrowband frequency chirp and a frequency-shifted replica. The narrowband chirp has an optical carrier frequency, a pulse duration and a pulse bandwidth. A frequency-shifted replica is generated by frequency shifting the narrowband chirp by a frequency shift. Adding the frequency-shifted replica after a start of the narrowband chirp by a delay generates a broadband frequency chirp. Alternatively, the frequency-shifted replica is generated by frequency shifting a constant frequency pulse, and modulating the frequency-shifted pulse to generate narrowband chirps that are added to form the broadband chirp.

Abstract: A method for imaging a sample is described. The sample is characterized by a limit on incident optical energy absorbed over a given time period. The method includes providing at least one input optical wave that includes pulses that each have a full-width half-maximum time duration of more than 100 picoseconds and a pulse energy sufficiently large such that a sufficient number of consecutive pulses absorbed by the sample would exceed the limit. The method also includes directing the input optical wave to focus on a first portion of the sample; detecting energy from an output optical wave generated from a nonlinear optical interaction in the first portion of the sample with the input optical wave; and generating a representation of the first portion of the sample based on the detected energy from the output optical wave.

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

Abstract: An Interferometric Modulator (IMod) is a microelectromechanical device for modulating light using interference. The colors of these devices may be determined in a spatial fashion, and their inherent color shift may be compensated for using several optical compensation mechanisms. Brightness, addressing, and driving of IMods may be accomplished in a variety of ways with appropriate packaging, and peripheral electronics which can be attached and/or fabricated using one of many techniques. The devices may be used in both embedded and directly perceived applications, the latter providing multiple viewing modes as well as a multitude of product concepts ranging in size from microscopic to architectural in scope.

Abstract: This application describes designs, implementations, and techniques for controlling propagation mode or modes of light in a common optical path, which may include one or more waveguides, to sense a sample.

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 first optical waveguide, a second optical waveguide, a first electrode, and a second electrode are integrated on a substrate. An optical modulator is provided with a clock signal generator for generating an RZ signal by applying a clock signal to either the first or second electrode, and an NRZ data signal generator for supplying an NRZ data signal to the remaining electrode. Thus, the space required by the optical modulator is reduced while tolerance of the same is improved, thus reducing costs for constructing the optical modulator.

Abstract: An extended optical sensor comprises a plurality of equally spaced intensity-based point sensors connected in parallel such that the optical path lengths are the same within the extended sensor enclosure. The input to the extended sensor is a single optical fiber as is the output.