Abstract: A laser radar device performs control to make a focus distance of transmission light equal to a measurement distance by switching a plurality of laser light sources that emit beams of oscillation light having wavelengths different from each other to switch emission directions of the transmission light while maintaining the focus position of optical antennas, and changing the wavelength of the beams of oscillation light according to the measurement distance.

Abstract: Lighting system includes light source that includes at least one light-emitting device and emits first light (laser light); wavelength conversion member that converts part of the first light into second light having a different wavelength from that of the first light; an optical system (light guide member) where the first light enters and that applies the first light to wavelength conversion member; optical sensor that receives part of the second light as monitor light and outputs monitor signal corresponding to the intensity of monitor light; and output control circuit that controls light source and optical sensor. Output control circuit performs an optical system inspection of conditions of the optical system and wavelength conversion member and a light source inspection of a condition of light source in accordance with monitor signal, using a time division method.

Abstract: Lighting system includes light source that includes a plurality of light-emitting devices and emits first light; wavelength conversion member that converts part of the first light into second light; an optical system that applies the first light to wavelength conversion member; optical sensor that output monitor signal corresponding to the intensity of the second light; and output control circuit that controls light source and optical sensor. Output control circuit performs a light source inspection of a condition of light source and an optical system inspection of conditions of the optical system and wavelength conversion member in accordance with monitor signal. In the light source inspection, the output control circuit inspects each of light-emitting devices in sequence, and after having inspected one of light-emitting devices, suspends the light source inspection and performs the optical system inspection before inspection of another one of the light emitting devices.

Abstract: A laser oscillation device includes a laser oscillation unit, which is a laser oscillation part that generates multiple first laser beams having different wavelengths from one another, multiple sensors having different sensitivity characteristics from one another each representing light-receiving sensitivity for the wavelengths of the multiple first laser beams, to each output first voltages dependent on outputs of the multiple first laser beams. The laser oscillation device includes a computing unit that corrects the multiple first voltages using the sensitivity characteristics of the multiple sensors, and controls the laser oscillation unit based on multiple second voltages which correspond to multiple first voltages obtained after the correction.

Abstract: An optical touch-sensitive device is able to determine the locations of multiple simultaneous touch events. The optical touch-sensitive device can include an optical waveguide, an emitter, and an emitter coupler. The emitter produces optical beams, and the emitter coupler is on a surface of the waveguide and is configured to direct at least some of the optical beams to propagate via total internal reflection (TIR) through the waveguide as coupled optical beams. Touches on the top surface of the waveguide disturb the coupled optical beams, and the touch-sensitive device determines touch events based on the disturbances.

Abstract: A method may include causing a signal to be transmitted that includes a plurality of wavelengths. The signal may be transmitted via an optical fiber that is associated with a particular wavelength. The particular wavelength may be included in the plurality of wavelengths. The method may include filtering the signal, based on the particular wavelength, to generate a filtered signal. The filtered signal may include the particular wavelength. The method may include detecting the filtered signal in association with the optical fiber. The method may include determining the particular wavelength based on the filtered signal. The method may include storing or providing information identifying at least one of the particular wavelength, the optical fiber, or a transmitter that transmitted the signal.

Abstract: A wavelength monitor includes: a wavelength tunable laser (1) having a plurality of emitting ports (10, 11), from which laser beams of the same wavelength are emitted; collimating lenses (20, 21) , which are configured to collimate the laser beams emitted from the emitting ports (10, 11) to emit the collimated laser beams; an optical filter (4) having a periodic transmittance with respect to a frequency, on which the laser beams emitted from the collimating lenses (20, 21) are incident; and an optical detector (5) configured to receive the laser beams that have passed through the optical filter (4) to detect light intensities of the laser beams. In the wavelength monitor, the collimating lenses (20, 21) and the optical filter (4) are disposed so that the laser beams are incident on the optical filter (4) while a condition expressed as Equation (1) is satisfied.

Abstract: A spectroscopic apparatus and method for analyzing a biological material are provided. The spectroscopic apparatus may analyze a biological material which has an internal non-uniform tissue depending on a position thereof. The apparatus may include at least one detector configured to obtain respective detection spectrums corresponding to a plurality of measurement regions that are at mutually different positions of the biological material, and an information processor to determine whether the measurement regions are normal by mutually comparing the detection spectrums, or converting contribution degrees of data for a specific component of the biological material by differentiating the detection spectrums.

Abstract: Systems and methods for calibrating, operating, and setting the magnitude of the power of light provided by a laser diode in a conducted electrical weapon (“CEW”). The light of the laser diode assists in targeting by providing a visible indication of the projected point of impact of the tethered electrode of the CEW. The calibration process enables laser diode of a CEW to operate within regional guidelines of the maximum output power of light permitted by a laser. The method further permits the magnitude of the power of the light provided by a laser diode to be set and operated in changing environmental conditions in the field.

Abstract: Resonant meta-material structures are defined by metallic, dielectric or other materials that form nanoshells or nanomeshes that can be situated proximate to ionizing-radiation-sensitive layers so as to provide ionizing-radiation-dose-dependent optical properties. Such meta-material structures can also define aligned or periodic, semi-random, or other arrangements of nanostructures that are coupled to or include stressed layers. Detection of optical radiation from such structures is used to determine gamma radiation dose or to detect a disturbance of the nanostructure indicating tampering.

Abstract: A media-defined optical logic circuit composed of a set of light-transmitting polyhedral prisms arranged so that a pair of adjacent prisms can exchange photonic signals through adjacent surfaces. Each prism contains one or more quantum dots that, when excited by a photonic signal received from an adjacent prism, respond by emitting light that becomes an incoming photonic signal for an adjacent prism. Photonic signals are propagated through the circuit in this manner along light-guide paths created by shading certain surfaces to render them fully or partially opaque. The prisms and shading are arranged such that the circuit performs a certain logic function. When the circuit receives a set of photonic input signals representing a binary input value, the circuit responds by emitting a set of photonic output signals that represent a binary output value determined by performing the logic function upon the binary input value.

Abstract: The present invention relates to a system for recirculating the gas atmosphere within an excimer laser system, where contaminates, created in the laser's operation, are removed, and the gas concentrations of additive gases, such as Xe, Kr, or others, depleted in the laser operation, are rebalanced to specific lasing mixtures by analyzation and component replenishment from one or more external supplies.

Abstract: A light emitting device includes: a base; at least one semiconductor laser element disposed on the base and configured to emit light laterally; a reflecting member that is disposed on the base; a surrounding part that is disposed on the base and that surrounds the at least one semiconductor laser element and the reflecting member; a wiring part that is electrically connected to the at least one semiconductor laser element and that is disposed on an upper surface of the base so as to extend laterally to a location on the upper surface of the base that is laterally outside of the surrounding part; a radiating body disposed on the surrounding part, the radiating body comprising at least one of a metal and a ceramic, and the radiating body having an opening; and a wavelength converting member that is located in the opening of the radiating body.

Abstract: A radiation source includes a semiconductor substrate, an array of vertical-cavity surface-emitting lasers (VCSELs) formed on the substrate, which are configured to emit optical radiation, and a transparent crystalline layer formed over the array of VCSELs. The transparent crystalline layer has an outer surface configured to diffuse the radiation emitted by the VCSELs.

Abstract: A pulse width modulation system comprises an analog component and a digital component. The analog component operates to separate a local oscillator signal with different phase shifts and introduce an offset (i.e., a time delay) to analog signals being receive at an input with a tuning operation that fine tunes in the analog signals in the analog (continuous time) domain. The analog component comprises a plurality of analog delay lines that respectively process carrier signals having a different phase shifts. Digital delay lines convert the analog signals to digital square waves with the same time delay and at the same resolution as the analog output signal.

Abstract: A system includes a master oscillator configured to generate a low-power optical beam. The system also includes a planar waveguide (PWG) amplifier configured to amplify the low-power beam into a high-power output optical beam, where the PWG amplifier has a larger dimension in an unguided direction and a smaller dimension in a transverse guided direction. The system further includes an adaptive optic configured to pre-distort the low-power optical beam substantially along a single dimension prior to injection of the low-power optical beam into the PWG amplifier in order to compensate for thermal-based distortions created by the PWG amplifier. The single dimension represents the unguided direction. In addition, the system includes a feedback loop configured to control the adaptive optic.

Abstract: A plurality of networked lighting devices are deployed in a parking garage. The lighting devices each have a display, a controllable general illumination light source, and an occupancy sensor. When a user enters the parking garage in a vehicle, the display of lighting devices outputs directional arrows and communicates with other lighting devices to direct the user to a vacant parking space (e.g., displays green). In response to detecting that the vehicle has parked in a parking space, the display output is adjusted (e.g., displays red) and the general illumination light source is changed to a different lighting state. Hence, when the user pulls into the parking space, illumination lighting is activated to a brighter setting. The illumination lighting is adjusted to the brighter setting as the user approaches other lighting devices, for example, when approaching an elevator or later re-approaches the vehicle to provide a feeling of safety.

Abstract: A remote unit (1) that controls a control target (4) on the basis of a command from a CPU unit (2) is provided with: an external input section (11) to receive a detection result of a state of the control target from a detection means (3) that detects the state of the control target; an output section (13) to output a control output for controlling the control target; and an abnormality determining section (12) to determine an abnormality of the control target on the basis of the detection result and to output to the output section, a control instruction to instruct a change or a stop of the control output if the control target is determined to be abnormal.

Abstract: An optical system includes a laser cavity on a base. The laser cavity generates a light signal in response to application of an electrical current to the laser cavity. The system includes first electronics that apply a target level of the electrical current to the laser cavity so as to cause the laser cavity to generate the light signal. The light signal experiences mode hops at electrical current levels that shift to higher current levels in response to increasing laser operation times. A first one of the mode hops occurs at a first current level and a second one of the mode hops occurs at a second current level that is higher than the first current level. The system also includes a phase shifter that interacts with the laser cavity so as to shift the mode hops to lower current levels than occur in the absence of the phase shifter.

Abstract: A method and apparatus for modulating a beam from a laser with an electro-absorption modulator, and determining the optical power of the beam by measuring a back current produced by the electro-absorption modulator. The apparatus comprises an electro-absorption modulator and a back current detector. The electro-absorption modulator receives an electronic digital signal from an electro-absorption driver. The electro-absorption modulator modulates the beam of the laser according to the electronic digital signal. While modulating the beam, the electro-absorption modulator produces a back current. This back current is proportional to the optical power of the beam. The back current detector measures the back current to determine the optical power of the beam.

Abstract: Disclosed is an integrated circuit (IC) chip incorporating a temperature-sensitive element and temperature stabilization circuitry for ensuring that the temperature of the temperature-sensitive element (TSE) remains essentially constant. The IC chip comprises a temperature-sensitive element and, within at least one region adjacent to the temperature-sensitive element, a first circuit that radiates a first heat amount to the TSE and a second circuit that radiates a second heat amount to the TSE. The second circuit senses changes in a first current amount in the first circuit and, thereby changes in the first heat amount. In response to those changes, the second circuit also automatically adjusts a second current amount in the second circuit and, thereby the second heat amount in order to ensure that the total heat amount radiated by the first circuit and the second circuit, in combination, to the TSE remains constant. Also disclosed is an associated method.

Abstract: A laser irradiation apparatus which is provided with: an environment isolation container, which houses a laser oscillator and is disposed in water; a laser irradiation head, which collects laser beams and irradiates a part to be machined with the laser beams; a light guide section which transmits the laser beams from the laser oscillator to the laser irradiation head; a power supply apparatus which supplies the laser oscillator with power; a cooling water supplying apparatus, which supplies the laser oscillator with cooling water through a cooling water supplying path; and a temperature sensor which measures the temperature inside of the environment isolation container. The temperature and/or the flow quantity of the cooling water to be supplied from the cooling water supplying apparatus is controlled on the basis of the measurement results obtained from the temperature sensor.

Abstract: A method for sweeping an electromagnetic radiation source (12) to produce single mode operation having an optimized side-mode suppression ratio over a continuous range of wavelengths within a prescribed temporal profile, the electromagnetic radiation source is configured to output electromagnetic radiation at a given wavelength based upon parameters. The method includes determining a set of parameter combinations that satisfy a condition for a desired set of wavelengths and a maximum side mode suppression ratio over the range of wavelengths. The set of parameter combinations define sub-paths for transitioning from one wavelength to another wavelength. Combinations of select sub-paths provide a multivariate path for transitioning over the range of wavelengths. The method also includes controlling the semiconductor laser to emit electromagnetic radiation over the range of wavelengths by traversing the multivariate path in a desired manner.

Abstract: A method for controlling wavelength tunable laser comprises the steps of inputting information specifying a first wavelength, determining whether or not the first wavelength is identical to a second wavelength coinciding with any of the fundamental wavelengths stored in the first memory, acquiring a drive condition for the second wavelength from the first memory when it is determined that the first and second wavelengths are identical to each other, calculating a drive condition at the first wavelength, when it is determined that the first and second wavelengths differ from each other, by acquiring the drive condition for the second wavelength from the first memory and using the drive condition according to the difference between the first and second wavelengths, and controlling an lasing wavelength of the wavelength tunable laser according to the drive condition in the acquiring step or calculating step.

Abstract: A radiation-emitting component is specified, having a metallic carrier body (1), which comprises at least two connection locations (1a, 1b) for making electrical contact with the component, a laser diode chip (2), which is fixed to the metallic carrier body (1) and is electrically conductively connected to the at least two connection locations (1a, 1b), a housing (3), which surrounds the metallic carrier body (1) in places, wherein the housing (3) is formed with a plastic, the connection locations (1a, 1b) extend in each case at least in places along a bottom face (3a) and a side face (3b) of the housing (3), said side face running transversely with respect to the bottom face, and the component is surface-mountable by means of the connection locations (1a, 1b) in such a way that the bottom face (3a) or the side face (3b) forms a mounting face of the component.

Abstract: An electronic light detection circuit for detecting an intensity modulated light signal on a photosensitive element under backlight condition. The circuit comprises the photosensitive element, in particular as a light position detector for detecting a striking position of the light signal spot within a detection window, an amplifier with high input resistance connected to an output of the photosensitive element and a backlight suppression circuitry. The backlight suppression circuitry is connected to the output of the photosensitive element in parallel to the amplifier and comprises an electronic active resonator structure. The active resonator, structure is designed in such a way to provide a load impedance to an output of the photosensitive element with a low load impedance for low frequencies for suppression of natural and artificial backlight-saturation of the photosensitive element and a high load impedance at the frequency of the intensity modulated light signal.

Abstract: A composite laser gain medium is comprised of a first rare-earth element doped core; and a second rare-earth element doped cladding, at least partially, adjacent to the core. A portion of the lasing by the cladding at one wavelength within the composite laser gain medium is absorbed by the core so as to cause lasing of the core at a different wavelength. At least two distinct rare earth element pairs may be used in embodiments: (1) thulium (Tm) as a cladding rare-earth dopant and holmium (Ho) as the core rare-earth dopant; and (2) ytterbium (Yb) as a cladding rare-earth dopant and erbium (Er) as the core rare-earth dopant. Other rare earth element pairs are also believed possible. The laser composite gain medium may be configured to have a slab, or a cylindrical geometry.

Abstract: A hybrid external cavity laser (HECL) system comprises a diode laser, collection and collimation optics, and a volume Bragg grating, emits radiation at a single wavelength with a short-term wavelength stability in the order of at least one part in a billion The wavelength stability is achieved by use of a thermal management system, comprising inner and outer housings, each containing a temperature sensor, and electronic circuitry that monitors the temperatures and controls both the laser diode current and a thermoelectric cooler based on temperatures determined from said temperature sensors. The laser system is packaged in a compact enclosure that minimizes waste heat, facilitating use in applications that have heretofore employed stable, single-frequency lasers, including He—Ne lasers.

Abstract: A variable wavelength diode according to the inventive concept includes a resonator and a plurality of cylindrical lenses. The resonator includes slab waveguides of which resonance lengths are different from each other. The slab waveguides are disposed on a planar light wave circuit (PLC). Thus, the variable wavelength diode realizes a high variation speed and a continuous variation of a beam at the same time.

Abstract: A laser source (10) for emitting an output beam (12) along an output axis (12A) includes (i) a first laser module (16) that generates a first beam (16A); (ii) a second laser module (18) that generates a second beam (18A); (iii) a beam selector assembly (32); (iv) a first director assembly (24) that directs the first beam (16A) at the beam selector assembly (32); (v) a second director assembly (26) that directs the second beam (18A) at the beam selector assembly (32); and (vii) a control system (34) that directs power to the modules (16), (18). The beam selector assembly (32) moves between a first position in which the first beam (16A) is directed along the output axis (12A), and a second position in which the second beam (18A) is directed along the output axis (12A).

Abstract: In a method of stabilizing pump energy, a gain medium is provided having an absorption coefficient that varies with wavelength. An absorption coefficient curve of the absorption coefficient or a range of wavelengths comprises peaks and valleys. Pump energy is generated at an operating wavelength within one of the valleys, at which the absorption coefficient is approximately at a minimum. The pump energy is transmitted through the gain medium. A portion of the pump energy is absorbed with the gain medium and laser light is emitted from the gain medium responsive to the absorbed pump energy. The non-absorbed pump energy (feedback pump energy) is fed back to the pump module. The operating wavelength of the pump energy is stabilized using the feedback pump energy.

Abstract: Method for shielding a high-power laser apparatus (S) in which a laser beam is generated and then amplified in at least a first amplification stage, including spatial filtering (4) of the amplified laser beam, phase correction (3) carried out on the laser beam before it is spatially filtered, and a measurement of the aberrations (7) on the laser beam. The phase of the beam is corrected so as to produce a beam having minimal aberrations after spatial filtering. The shielding device (D, D?) implementing this method may in particular be employed in apparatus using an intense laser beam of high (terawatt) peak power and in proton therapy units.

Abstract: A method for determining stabilization of a light output signal employed by a laser frequency stabilizing device which irradiates laser light on an absorption cell to obtain the light output signal and, based on a saturated absorption line contained in the light output signal, changes a resonator length to stabilize an oscillation frequency of the laser light to a specific saturated absorption line. The laser frequency stabilizing device includes a conversion mechanism converting the laser light that passes through the absorption cell into the light output signal, an actuator changing the resonator length, and a control mechanism controlling operation of the actuator. The method for determining stabilization includes a signal analysis step analyzing the light output signal and a stabilization determination step determining whether the light output signal is stabilized based on an analysis result from the signal analysis step, executed by the control mechanism.

Abstract: The invention is an apparatus and method for free space pumping of active double-clad fiber based lasers and amplifiers. The apparatus comprises a laser emitting a signal laser beam; an active double-clad fiber having a core defining an optical axis of the apparatus and a pump cladding defining a cone of numerical aperture; an optical arrangement directing the signal laser beam along the optical axis through the core of the active double-clad fiber; at least one pump source emitting a pump beam; at least one delivery means coupling the pump beam to the pump cladding of the active double-clad fiber; and an optical arrangement coupling the amplified signal laser beam exiting the active double-clad fiber out of the apparatus.

Abstract: A laser anti-reflection device includes a polarizing beam splitter, a ?/4 wave plate and an absorber disposed in an outgoing light path of a laser emitting linearly polarized light with a wavelength of ?. The linearly polarized light from the laser passes through the polarizing beam splitter and the ?/4 wave plate in turn to become a circularly polarized light beam. Part of the circularly polarized light beam is then reflected by a workpiece to be processed along the original light path and passes the ?/4 wave plate to become a linearly polarized light beam with a polarization direction vertical to that of the outgoing linearly polarized light beam. The vertical polarized beam passes the polarizing beam splitter, deviates from the light path of the outgoing linearly polarized light beam and reaches the absorber. The laser anti-reflection device prevents reflected light from damaging the laser from high power lasers.

Abstract: In a method, a gain medium is provided having an absorption coefficient that varies with wavelength. An absorption coefficient curve of the absorption coefficient or a range of wavelengths comprises peaks and valleys. A pump module is operated to output pump energy at an operating wavelength within one of the valleys, at which the absorption coefficient is approximately less than 40% of the absorption coefficient at an adjacent peak of the absorption coefficient curve defining the valley. The pump energy is directed through the gain medium. A portion of the pump energy is absorbed with the gain medium and laser light is emitted from the gain medium responsive to the absorbed pump energy. The non-absorbed pump energy (feedback pump energy) is fed back to the pump module. The operating wavelength of the pump energy is stabilized using the feedback pump energy.

Abstract: Embodiments of the present invention use an external cavity laser source with dual input terminals, such as bias current for a gain section, and a voltage signal for a modulator section. An aspect of the present invention provides an ultra-low frequency noise external cavity frequency modulated (FM) semiconductor laser source frequency stabilized by a dual electronic feedback circuitry applied to semiconductor gain section and a modulation section. A further aspect of the present invention provides an optical frequency discriminator based on homodyne phase demodulation using an unbalanced Michelson interferometer with fiber optics delay and a symmetrical 3×3 optical coupler.

Abstract: A beam-stabilized laser system using optical frequency conversion in a nonlinear optical crystal is disclosed. An optimal phase-matching angle in the crystal depends on both wavelength and temperature. If the crystal temperature changes, the optimal phase-matching direction will change as well. A different wavelength can be selected so that the optimal phase-matching occurs along the original beam path and returns the output beam to the original direction. Thus, a central wavelength of the laser beam illuminating the nonlinear optical crystal can be slightly adjusted to compensate for the pointing drift. Since the illuminating wavelength can normally be tuned much faster than the crystal temperature, a more agile and responsive pointing stabilization can be achieved.

Abstract: A method and device are provided for fast, continuous tuning of an optical source. A first pump signal with a first pump frequency is input into a mixer along with a first seed signal having a first seed frequency. Within the mixer, the first pump signal and the first seed signal generate at least one idler having an idler frequency defined as two times the pump frequency minus the seed frequency. Shifting the pump signal across a frequency range at a sweep rate causes the idler frequency to be shifted by two times the frequency range at two times the sweep rate. The shifted at least one idler is mixed with the shifted pump signal to generate a first mix product that has two times the sweep rate and frequency range of the pump signal.

Abstract: A mode-locked laser system operable at low temperature can include an annealed, frequency-conversion crystal and a housing to maintain an annealed condition of the crystal during standard operation at the low temperature. In one embodiment, the crystal can have an increased length. First beam shaping optics can be configured to focus a beam from a light source to an elliptical cross section at a beam waist located in or proximate to the crystal. A harmonic separation block can divide an output from the crystal into beams of different frequencies separated in space. In one embodiment, the mode-locked laser system can further include second beam shaping optics configured to convert an elliptical cross section of the desired frequency beam into a beam with a desired aspect ratio, such as a circular cross section.

Abstract: A diode laser is provided with wavelength stabilization and vertical collimation of the emitted radiation, which allows a small distance of the volume Bragg grating from the emitting surface, a small vertical diameter of the collimated beam and also compensation for manufacturing tolerances affecting the shape of the grating and the lens. The diode laser comprises an external frequency-selective element for wavelength stabilization of the laser radiation, wherein the external frequency-selective element comprises an entry surface facing the exit facet and an exit surface facing away from the exit facet and is designed as a volume Bragg grating; and wherein the external frequency-selective element is designed in such a manner that the divergence of the radiation emitting from the exit facet is reduced during passage through the external frequency-selective element.

Abstract: A laser device (100) includes a laser (110; 210; 310; 410; 510) in turn including at least one Distributed Bragg Reflector (DBR) section (111), at least one phase section (112) and at least one gain section (113), further including a laser control element (150), a feedback control element (140) and a frequency noise discriminator (130,131), which feedback control element is arranged to feed a variable feedback signal to at least one of the at least one DBR section and the at least one phase section of the laser, so that the output laser frequency is altered in response to a variation in the feedback signal or the combination of respective feedback signals, whereby the feedback signal or combination of respective feedback signals is varied as a function of the detected frequency fluctuation so as to counteract the detected frequency fluctuation.

Abstract: Signal generating systems and methods are described. One signal generation system includes first and second lasers configured to generate first and second laser beams having respective frequencies wherein a difference in the respective frequencies corresponds to an output frequency, a photodetector configured to produce a signal at the output frequency, and first and second electro-optic modulators configured to respectively electro-optically modulate the first and second laser beams using the signal to produce respective first and second modulated optical signals, each of the first and second modulated optical signals having a respective sideband corresponding to the frequency of the other one of the first and second laser beams. The first laser is seeded with the respective sideband of the second modulated optical signal and the second laser is seeded with the respective sideband of the first modulated optical signal to phase-lock the first and second laser beams to each other.

Abstract: An optical power stabilizing device is adapted to stabilize optical power of a light emitting device having a forward voltage, and includes a current generating circuit that generates a pulse-wave driving current to drive light emission of the light emitting device, an optical-type feedback circuit that outputs a first feedback voltage according to detected optical power of the light emitting device, an electrical-type feedback circuit that outputs a second feedback voltage according to the forward voltage, and a pulse wave generating circuit that generates a pulse-wave signal to control the current generating circuit according to one of the first feedback voltage and the second feedback voltage.

Abstract: Techniques and devices based on optical resonators made of nonlinear optical materials and nonlinear wave mixing to generate optical combs that are stabilized relative to an atomic reference.

Abstract: There is discussed an optical system comprising a laser device that outputs a divergent light beam. A first portion of the divergent light beam, including a central portion, passes through an etalon device, which acts as a wavelength discriminator, and then the central portion is incident on a first monitor photodiode, which generates a wavelength-dependent detection signal. A second portion of the divergent light beam is incident on a second monitor photodetector, without passing through the etalon device, to generate a wavelength-independent detection signal. A processor processes the wavelength-dependent detection signal and the wavelength-independent detection signal to determine a control signal for controlling the wavelength of the laser device. By accurately positioning a photodetector at the central fringe of the divergent light beam following transmission through the etalon device, a compact and cost-effective wavelength locking arrangement is provided.

Abstract: A semiconductor laser outputs a laser light from an output facet of a waveguide having an index waveguide structure, via a lens system. The waveguide includes, in order from a rear facet opposite to the output facet, a first narrow portion, a wide portion that is wider than the first narrow portion, a second narrow portion narrower than the wide portion, a first tapered portion formed between the first narrow portion and the wide portion, which expands toward the wide portion, and a second tapered portion formed between the wide portion and the second narrow portion, which narrows toward the second narrow portion. Each of the first narrow portion, the wide portion, and the second narrow potion has a uniform width.

Abstract: An upper limit and a lower limit are preliminarily set for a spectral line width common to a plurality of narrow-band laser devices. When delivered or subjected to maintenance, the narrow-band laser device is caused to laser oscillate to detect its spectral line width before it is used as a light source for semiconductor exposure. A spectral line width adjustment unit provided in the narrow-band laser device is adjusted so that the spectral line width assumes a value between the upper limit and the lower limit. The present invention is able to suppress the variation in spectral line width such as E95 bandwidth caused by machine differences during the manufacture of the laser device, or by replacement or maintenance of the laser device, whereby the quality of integrated circuit patterns formed by the semiconductor exposure tool can be stabilized.

Abstract: This description relates to an apparatus, a method of manufacturing, and a method of tuning optical and/or electrical parameters of semiconductor devices and materials, thin film materials, or other devices. In one example, a laser is tuned to produce an adjustable output wavelength by coupling the laser to a tuning material or base such as, for example, a piezoelectric base using a suitable attachment method. The laser includes of a tunable material that is sensitive to stress and/or strain. Stress and/or strain applied to the laser from the tuning material results in an electronically variable output wavelength. As an example, applying a voltage to a piezoelectric base that serves as a tuning material can cause the base to expand or contract, and the expansions and contractions from the base are coupled to the tunable material of the laser, thus varying the wavelength of the output light from the laser.

Abstract: Embodiments of an ultra-stable frequency reference generating system and methods for generating an ultra-stable frequency reference using a two-photon Rubidium transition are generally described herein. In some embodiments, a cavity-stabilized reference laser comprising a laser source is locked to a stabilized cavity. A Rubidium cell is interrogated by a stabilized laser output to cause at least a two-photon Rubidium transition and a detector may detect fluorescence resulting from spontaneous decay of the upper state Rubidium transition. The output of the detector is provided at a wavelength of the fluorescence to lock the cavity-stabilized reference laser to generate a stabilized laser output. A frequency comb stabilizer may be locked to the stabilized laser output to generate a super-continuum of optical wavelengths for use in generating an ultra-stable frequency reference.