Abstract: The present disclosure relates to an approach for monitoring the output power of a VCSEL or VCSEL array in a relatively compact, low profile package. A VCSEL device or VCSEL package of the present disclosure may generally be configured with a photodiode for monitoring output power of one or more VCSELs. In some embodiments, one or more VCSEL devices may be arranged over or on a photodetector, such that the photodetector is configured to detect light emitted through a bottom of the VCSEL. In such embodiments, the VCSEL device may have a patterned bottom metal layer and/or an etched substrate to allow light to pass below or behind the VCSEL to the photodiode. In other embodiments, a photodetector may be arranged on a submount adjacent one or more VCSELs, and may be configured to detect light reflected via a diffuser in order to monitor output power.

Abstract: The present disclosure relates to an approach for monitoring the output power of a VCSEL or VCSEL array in a relatively compact, low profile package. A VCSEL device or VCSEL package of the present disclosure may generally be configured with a photodiode for monitoring output power of one or more VCSELs. In some embodiments, one or more VCSEL devices may be arranged over or on a photodetector, such that the photodetector is configured to detect light emitted through a bottom of the VCSEL. In such embodiments, the VCSEL device may have a patterned bottom metal layer and/or an etched substrate to allow light to pass below or behind the VCSEL to the photodiode. In other embodiments, a photodetector may be arranged on a submount adjacent one or more VCSELs, and may be configured to detect light reflected via a diffuser in order to monitor output power.

Abstract: An optical system comprising an optoelectronic device having a facet and a coating on the facet. The facet is configured to be in optical communication with at least a first optical medium during a first time period and a second optical medium during a second time period. The first optical medium has a first refractive index and the second optical medium has a second refractive index different from the first refractive index. The coating is configured to provide a first reflectance during the first time period for optical signals in a predetermined wavelength range and to provide a second reflectance during the second time period for optical signals in the predetermined wavelength range wherein the second reflectance is equal to the first reflectance within a negligible margin for optical signals having at least one wavelength in the predetermined wavelength range.

Abstract: A disclosed semiconductor laser module includes a semiconductor laser device; a semiconductor optical amplifier configured to receive laser light emitted from the semiconductor laser device and amplify the laser light that has been received; and a first light receiving device that measures an intensity of a part of the laser light emitted from the semiconductor laser device, for monitoring a wavelength of the laser light, wherein the semiconductor optical amplifier is located rearward in relation to a light receiving surface of the first light receiving device along a propagation direction of the laser light emitted from the semiconductor device.

Abstract: A broadband optical amplifier for operation in the 2 ?m visible wavelength band is based upon a single-clad Tm-doped fiber amplifier (TDFA). A compact pump source uses a combination of low-power laser diode with a fiber laser to provide a multi-watt pump beam without needing to include thermal management and/or pump wavelength stability components. The broadband optical amplifier is therefore able to be relatively compact device with fiber coupled output powers of >0.5 W CW, high small signal gain, low noise figure, and large OSNR, important for use as a versatile wideband preamplifier or power booster amplifier.

Abstract: In various embodiments, one or more prisms are utilized in a wavelength beam combining laser system to regulate beam size and/or to provide narrower wavelength bandwidth.

Abstract: A level-shifter includes an input node coupled to a laser driver input receiving a trigger signal, the input node receiving a signal indicating generation of a laser drive-pulse. A p-channel transistor has a source coupled to a supply node, a drain coupled to an output node, and a gate coupled to the input node. An n-channel transistor has a drain coupled to the drain of the p-channel transistor, a source coupled to ground, and a gate coupled to the input node. A first switch couples the input node to the output node. Another p-channel transistor has a source coupled to the supply node, a drain coupled to the output node by a second switch, and a gate coupled to the input node. The first switch closes and second switch opens when the signal is low, and the first switch opens and second switch closes when the signal is high.

Abstract: A laser projection system having built-in safety systems is disclosed. Further disclosed is a method of operating a laser projection system such that safe operation is a factor only of meeting a threshold distance between the laser unit and an audience member. To accomplish safe operation at the threshold distance, the laser projection system is pre-calibrated to operate below maximum permitted exposure levels at the threshold distance. In this manner of operation, laser lighting can be accomplished by non-laser professionals without the complexity, external sensors, and need for calibration at the venue.

Abstract: A wavelength selection method for a tunable laser includes: obtaining a target wavelength; and calculating target resistance values of two thermistors, respectively, corresponding to the target wavelength. Each of the two thermistors is used to monitor the temperature of a corresponding one of two wavelength selection components. Each of the target resistance values is calculated according to a relationship between a wavelength drift and a resistance change of the corresponding thermistor and according to an initial wavelength and an initial resistance value of the corresponding thermistor corresponding to the initial wavelength. The method further includes: heating the two wavelength selection components to control their temperatures until real-time resistance values of the two thermistors reach the target resistance values, respectively; and stabilizing the real-time resistance values at the target resistance values and outputting a laser beam having the target wavelength.

Abstract: A laser assembly (1210) for generating an assembly output beam (1212) includes a laser subassembly (1216) that emits a plurality of spaced apart first laser beams (1220A), a plurality of spaced apart second laser beams (1220B), a transform lens assembly (1244), a wavelength selective beam combiner (1246), and a path length adjuster (1299). The transform lens assembly (1244) collimates and directs the laser beams (1220A) (1220B) to spatially overlap at a focal plane of the transform lens assembly (1244). The path length adjuster (1299) is positioned in a path of the first laser beams (1220A), the path length adjuster (1299) being adjustable to adjust of a path length the first laser beams (1220A) relative to the second laser beams (1220B).

Abstract: When performing failure prediction on an optical transceiver, the output optical power and an operational current of a transmission optical sub-assembly in the optical transceiver are recorded during the operation of the optical transceiver. A first ratio is acquired by dividing the average slope of the operational current recorded at a current time period by the average slope of the operational current recorded at an earlier time period. A second ratio is acquired by dividing the absolute average value of the slope of the output optical power recorded at the earlier time period by the absolute average value of the slope of the output optical power recorded at the current time period. When it is determined that the product of the first ratio and the second ratio is greater than a threshold value, a failure notification including life prediction information is provided.

Abstract: A laser assembly (10) for generating an assembly output beam (12) includes a laser subassembly (16) that emits a plurality of spaced apart laser beams (20), a beam adjuster (42), a transform lens (44A), a beam combiner (46), and an output coupler (48). The beam adjuster (42) adjusts the spacing between the plurality of laser beams (20). The transform lens (44A) focuses the laser beams (20) at a focal plane (54) and the beam combiner (46) is positioned at the focal plane (54). The beam combiner (46) combines the lasers beams (20) to provide a combination beam (58). Further, the output coupler (48) redirects at least a portion of the combination beam (58) back to the beam combiner (46) as a redirected beam (60), and transmits a portion of the combination beam (58) as the assembly output beam (12).

Abstract: The invention relates to a light module including a semiconductor laser element emitting a laser beam in a first cone of light, a photoluminescent element, and an optical means for transforming the light coming from the photoluminescent element into an exit light beam. The optical means has a guiding portion arranged to guide at least a portion of the light emitted in the first cone of light into a second cone of light and a device for detection of incident light. The light module comprises a means of deviation designed to deviate the light of the second cone of light toward a third cone of light directed toward the detection device arranged outside of the second cone of light.

Abstract: The present disclosure is directed to an optical device including at least one temperature-dependent tunable element for controlling a wavelength of an optical signal, a first sensor configured to indirectly monitor the optical signal, a second sensor configured to directly monitor the optical signal, and a control circuit. The tunable element may be one of (i) a laser for transmitting an outgoing optical signal and (ii) an optical filter coupled to a photodetector for receiving an incoming optical signal. The control circuit may be configured to receive first and second inputs from the first and second sensors, respectively, adjust the tuned wavelength of the tunable element from a first preselected wavelength to a second preselected wavelength based on the first input received from the first sensor, and maintain the tunable element at the second preselected frequency based on the second input received from the second sensor.

Abstract: A novel semiconductor device is provided. The semiconductor device includes a first resistor and a second resistor. The first resistor and the second resistor are electrically connected in series. A resistance material of the first resistor includes a metal oxide, and a resistance material of the second resistor is different from the resistance material of the first resistor. The semiconductor device is configured to output a voltage corresponding to the resistance values of the first resistor and the second resistor. The voltage reflects the properties of the resistance materials of the first resistor and the second resistor. The semiconductor device may include a circuit for processing this voltage. In that case, the first resistor can be stacked over the circuit, resulting in the downsizing of the semiconductor device.

Abstract: A device, including a first current supply configured to provide a bias current to a load and a main current supply having a source terminal coupled in parallel with the load and configured to reduce a current value to the load below the bias current, is provided. The device includes a termination resistor coupled in series with the source terminal of the main current supply and configured to receive current from the source terminal of the main current supply when the source terminal of the main current supply is activated. The device also includes an auxiliary current supply having a sink terminal coupled to the termination resistor at a common node, and configured to maintain the common node at common mode voltage when current flows from the source terminal of the main current supply to the sink terminal of the auxiliary current supply and through the termination resistor.

Abstract: In-line uni-directional optical tap detector devices provide optical power monitoring in a small, inexpensive form factor. A pair of optical fibers with angled end surfaces are fusion-spliced or butt-coupled together, with a thin-film coating or coating stack positioned in between the two fiber end surfaces. The thin-film coating or coating stack acts as an optical tap, reflecting a small portion of the optical signal towards a photo-detector affixed to the exterior of the cladding of the fibers, positioned and angled such that the photo-detector measures the optical power of signals propagating in one direction down the fibers, while ignoring signals propagating in the opposite, or reverse direction. Alternately, a V-groove block or fiber holder is used to position and secure the fibers, without requiring fusion splicing, where the reflection of a portion of the optical signal to the photo-detector may be due to Fresnel reflection at the fiber end surfaces.

Abstract: A method and apparatus provide for determining a temperature at a junction of a laser diode when the laser diode is operated in a lasing state that facilitates heat-assisted magnetic recording, comparing the junction temperature and an injection current supplied during the lasing state to stored combinations of junction temperature and injection current, and determining a likelihood of mode hopping occurring for the laser diode during the lasing state based on the comparison to stored combinations of junction temperature and injection current.

Abstract: Embodiments include techniques for device analysis and failure prediction, the techniques include measuring or collecting parametric data of the device at a configurable interval, wherein the parametric data includes one or more parameters, and receiving operating limits for the parametric data based on specifications or characteristics for the device. The techniques also include determining a trend of the measured or collected parametric data of the device, and filtering noise from the trend based at least in part on at least one of other devices exhibiting a deviation exhibited by the device or system state changes associated with system log files. The techniques include identifying a failure stage of the device based on at least one of the trend or the received operating limits, and transmitting a notification of a predicted failure based at least in part on the identification.

Abstract: A method of setting up a local broadband network contemplates using electronic circuitry to determine a geographic location of the electronic circuitry. The electronic circuitry can measure an actual condition of the local broadband network at the location and select an external function in the local broadband network dependent on the location and the actual condition. The method further contemplates electronic circuitry signaling at least the location and the external function to a central database via a common communication backbone. The electronic circuitry determines whether the local broadband network exceeds a network load threshold value, wherein falling below the network load threshold value causes the electronic circuitry to re-evaluate one or more connections in the local broadband network. The method contemplates that the electronic circuitry complies with a communication protocol of the local broadband network dependent on the external function.

Abstract: A light-emitting diode (“LED”) lighting unit includes an operational, a sense resistor electrically connected to the input of the operational amplifier, a first field effect transistor (“FET”) whose gate is electrically connected to the output such that the input voltage at the gate of the first FET rises and falls with the output voltage, a second FET whose gate is electrically connected to the output such that the input voltage at the gate of the second FET rises and falls with the output voltage, and a string of LED lights connected such that when the voltage across the string drops below a level to operate, the voltage across a sense resistor drops, causing the operational amplifier to increase its output until the input voltage at the gate of the second FET increases allowing one bank of LED lights to operate.

Abstract: A laser drive circuit compensates for laser diode dynamics. A compensation value is determined from a sum of weighted basis functions. The basis functions may be a function of current desired optical powers and/or past desired optical powers. The weights may be updated periodically based at least in part on accumulated basis function outputs and measured optical powers.

Abstract: A fiber optic voltage conditioner, and method therefor, generally relate to voltage conditioning. In such a fiber optic voltage conditioner, there is a laser, and an optical circulator is coupled to receive a light signal from the laser. A controller is coupled to the laser and is configured to generate first control information for wavelength-drift control of the laser. A data acquisition module is coupled to the controller and is configured to generate second control information for the controller for adjustment of the first control information. A photodetector is coupled to the optical circulator to receive a returned optical signal and is coupled to the data acquisition module to provide an analog output signal thereto. The photodetector is configured to generate the analog output signal responsive to the returned optical signal. The data acquisition module is configured to generate the second control information using the analog output signal.

Abstract: Components, systems, and methods for determining efficiency of an optical signal source in distributed communication systems are disclosed. Environmentally induced variations in the performance of optical sources used to convert electrical signals to optical signals (such as laser diodes) at the transmitters within the system can be evaluated in real time. Steps can be taken to compensate for these variations. The efficiency of the laser diode can be measured and provided to receivers in the distributed communication system. The receiver may use information related to the slope efficiency measurement to adjust the gain of the receiving amplifiers to provide desired adjustments to the gain. Thus, the receivers in the remote units (RU) receive information about the slope efficiency of the laser diodes at the head end equipment (HEE) and the HEE receives information about the slope efficiency of the laser diodes at the RU.

Abstract: Systems and methods are provided for regulating one or more currents. An example system controller includes: a thermal detector configured to detect a temperature associated with the system controller and generate a thermal detection signal based at least in part on the detected temperature; and a modulation-and-driver component configured to receive the thermal detection signal and generate a drive signal based at least in part on the thermal detection signal to close or open a switch to affect a drive current associated with one or more light emitting diodes. The modulation-and-driver component is further configured to, in response to the detected temperature increasing from a first temperature threshold but remaining smaller than a second temperature threshold, generate the drive signal to keep the drive current at a first current magnitude, the second temperature threshold being higher than the first temperature threshold.

Abstract: A method and apparatus provide for determining a temperature at a junction of a laser diode when the laser diode is operated in a lasing state that facilitates heat-assisted magnetic recording, comparing the junction temperature and an injection current supplied during the lasing state to stored combinations of junction temperature and injection current, and determining a likelihood of mode hopping occurring for the laser diode during the lasing state based on the comparison to stored combinations of junction temperature and injection current.

Abstract: A method for producing a plurality of semiconductor components and a semiconductor component are disclosed. In an embodiment the method includes applying a semiconductor layer sequence on a substrate, structuring the semiconductor layer sequence by forming trenches thereby separating the semiconductor layer sequence into a plurality of semiconductor bodies and applying an insulating layer covering the trenches and vertical surfaces of the plurality of semiconductor bodies. The method further includes forming a plurality of tethers by structuring the insulating layer in regions covering the trenches, locally detaching the substrate from the plurality of semiconductor bodies, wherein the tethers remain attached to the substrate and selectively picking up each semiconductor body by separating the tethers from the substrate, wherein each semiconductor body comprises a portion of the semiconductor layer sequence.

Abstract: An apparatus includes: a laser driver configured to output a laser diode current in accordance with a transmit data, a bias control code, and a modulation control code, a laser diode configured to receive the laser diode current and output a light signal, a photodiode configured to receive the light signal and output a photodiode current, a reference driver configured to output a reference current in accordance with the transmit data, the transmit enable signal, a reference bias code, and a reference modulation code, a two-fold comparison circuit configured to compare the photodiode current and the reference current and output a first decision and a second decision, and a DSP configured to adjust the bias control code and the modulation control code in accordance with the first decision and a second decision. A method provides reliable light output using the described apparatus.

Abstract: Examples of robust self-starting passively mode locked fiber oscillators are described. In certain implementations, the oscillators are configured as Fabry-Perot cavities containing an optical loop mirror on one cavity end and a bulk mirror or saturable absorber on the other end. The loop mirror can be further configured with an adjustable line phase delay to optimize modelocking. All intra-cavity fiber(s) can be polarization maintaining. Dispersion compensation components such as, e.g., dispersion compensation fibers, bulk diffraction gratings or fiber Bragg gratings may be included. The oscillators may include a bandpass filter to obtain high pulse energies when operating in the similariton regime. The oscillator output can be amplified and used whenever high power short pulses are required. For example the oscillators can be configured as frequency comb sources or supercontinuum sources. In conjunction with repetition rate modulation, applications include dual scanning delay lines and trace gas detection.

Abstract: An imager module having an interposer chip electrically connected to and routing signals between an image sensor, a printed circuit board (PCB), and a voice coil motor (VCM) is disclosed. In some example embodiments, one or more surface mount devices (SMDs) may further be attached to the interposer chip, the PCB, or both the interposer chip and the PCB. The interposer chip may further have a cavity therethrough to allow light to impinge in the image sensor. The interposer chip may still further have through silicon vias (TSVs) to route signals from the PCB to the VCM.

Abstract: A laser system comprises: a seed oscillator, having a seed output; dispersive optics, operative to receive the seed output and divide the seed output into spectrally separate seed components; an array of individually addressable, phase adjustable laser amplifiers corresponding to the spectrally separate components, each laser amplifier receiving as its seed one of the spectrally separate seed components and producing one of the spectrally separate amplified components; and phase actuators controlling the individually addressable, phase adjustable laser amplifiers. A method of operating a laser system comprises: generating a seed signal; dividing the seed signal into spectrally separate component signals; amplifying the spectrally separate component signals; recombining the spectrally separate component signals into an amplified output; and controlling phases of the amplified spectrally separate component signals. Both single-pass and double-pass amplifier array versions are disclosed.

Abstract: Methods and systems for determining material composition of a test sample may be provided. The test sample may be placed in a magnetic region having a magnetic field. A light beam may be directed at the test sample in the magnetic region. A birefringence in the light beam that has passed through the test sample may be detected. The material composition of the test sample may be determined based on the detected birefringence in the light beam.

Abstract: An optical network terminal is provided for use in a passive optical network (PON). The optical network terminal includes a data port for receiving data packets from an external device and a processor for converting the data packets to data link frames. In addition, the optical network terminal includes a memory configured to store a time division multiplexing scheme identifying a time slot assigned to each of a plurality of network nodes in the PON for transmission of upstream optical signals. An optical transceiver is provided for converting the data link frames to upstream optical signals and transmitting the optical signals on an upstream TDMA (time division, multiple access) channel to an Optical Line Terminal (OLT). The optical transceiver includes a burst mode laser diode for generating the optical signals and a burst mode laser driver for biasing the laser diode with a bias signal and a modulation bias signal. The laser driver includes a dual closed loop feedback control circuit.

Abstract: Methods, architectures, circuits, and/or systems for monitoring operating parameters and/or generating status indications associated with electronic device operation are disclosed. The method can include (i) monitoring a first operating parameter related to operation of the electronic device to determine a first parameter value, (ii) calculating a difference between the first parameter value and a predetermined value for the first operating parameter, (iii) monitoring a second operating parameter on which thresholds for operational warnings and/or alarms are based to determine a second parameter value, (iv) updating or changing the thresholds based on a predetermined change or event in the second parameter value, (v) comparing the difference to the updated or changed thresholds, and (vi) generating a corresponding one of the operational warnings and/or alarms when the difference crosses at least one of the thresholds in a predetermined direction.

Abstract: A high power pump ultra bright low-noise source is configured with a multimode (“MM”) seed source outputting a MM smooth, low-noise signal light at a desired wavelength in a wavelength range between about 974 and 1030 nm, a MM Yb fiber wavelength converter operative to convert emission of a plurality of high power (“HP”) semiconductor laser diodes at a sub-pump wavelength ?sp to a pump output at the desired wavelength ??, wherein ??=????sp<0/1?sp. The Yb-doped MM wavelength converter is configured with noise levels substantially identical to those of the low-noise signal light, brightness (“B”) substantially equal to ?×B, wherein n is a number HP semiconductor laser diodes, and B is brightness of each HP laser diode, and output power (“Po”) substantially equal to nPd, wherein Pd is a power of each HP laser diode, and n is the number thereof.

Abstract: A method of controlling a temperature of a semiconductor laser includes: controlling a supply current so that a temperature of a temperature control element is changed to a target temperature, the temperature control element controlling a temperature of the semiconductor laser by a temperature changing according to the supply current supplied to the temperature control element; and performing a control for maintaining a calculated value calculated by a digital filter at a threshold when it is detected that the calculated value reaches the threshold, the calculated value being the supply current for achieving the target temperature, the threshold being equal to or less than an output limit of the digital filter.

Abstract: Techniques are described for adaptive sampling qualification for extinction ration control. The techniques may be implemented in a laser driver assembly which includes a laser driver and a sampling loop configured to facilitate sampling of photodiode current produced by a monitor photodiode (MPD) of an optical transmitter assembly. The sampling loop comprises a low pass filter with reset, a digital-to-analog converter (DAC), and a comparator. The filter receives transmit (Tx) data provided to the laser driver and generates an output corresponding to a number of consecutive bits of a first type received in the transmit (Tx) data. The filter resets the output when a bit of a second type is received. The digital-to-analog converter (DAC) outputs a threshold signal. The comparator compares the output from the low pass filter and the threshold signal, and outputs a signal indicating when the photodiode current is to be sampled.

Abstract: A femtosecond laser based laser processing system having a femtosecond laser, frequency conversion optics, beam manipulation optics, target motion control, processing chamber, diagnostic systems and system control modules. The femtosecond laser based laser processing system allows for the utilization of the unique heat control in micromachining, and the system has greater output beam stability, continuously variable repetition rate and unique temporal beam shaping capabilities.

Abstract: The present invention provides, in at least one embodiment, a system and method for power control of lasers. The system includes a device's control signal fed into a laser. The laser can be a master oscillator power amplifier (MOPA) fiber laser. The device includes an equivalent model circuit representing at least one parameter of the laser, such as the gain fiber inversion in the power amplifier. The device measures the power at the equivalent model circuit. Then, the device uses its feedback signal to control and/or adjust the output power control signal fed into the laser based on the measured power. By controlling the power fed into the laser, the laser can be operated at much lower frequencies while keeping the laser power within acceptable limits.

Abstract: Technologies are generally described for implementing non-linear VCSEL equalization. In some examples, a rising edge tap parameter, a falling edge tap parameter, an equalization delay and a bias current may be used to equalize a data signal to be output from a VCSEL. A VCSEL model may be used to derive a VCSEL response to one or more isolated data pulses. The derived response may then be used to determine the rising and falling edge tap parameters and an equalization delay, based on a bias current value for the VCSEL and a data rate associated with the data signal. The data signal may then be adjusted based on the equalization delay and the rising and falling edge tap parameter and sent to the VCSEL for output. At the same time, the VCSEL may be biased with a bias current having the bias current value.

Abstract: A light source including a laser diode, and a method of operating a light source including a laser diode are disclosed. A driving current of the laser diode is dithered to cause a near-field light intensity distribution at an end facet to be perturbed, thereby reducing a time-averaged local intensity of the laser light at the end facet of the laser diode. The reduced time-averaged intensity reduces a possibility of a damage of the end facet.

Abstract: A semiconductor laser has an optical cavity comprising and active layer disposed between an n-side barrier layer and a p-side barrier layer. The active layer comprises alternating layers of a first and second material, and the n-side barrier layer and p-side barrier layer each comprise alternating layers of the first material and a third material. The materials are selected such that the layers of the second and third materials form quantum wells between the layers of the first material. A band gap Eg of the second material is arranged such that a proportion of electrons and holes that recombine across the band gap Eg recombine to emit photons at the lasing wavelength, the proportion decreasing with increasing temperature of the optical cavity.

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 the field of the production of very high frequencies, for example from 1 gigahertz to several terahertz, by beating the frequencies of two laser beams together, a device includes a resonant optical cavity having very stable dimensions receiving the beams, with for each beam, an interrogation device of the resonant cavity supplying an electrical signal representing the difference in frequency between the light frequency of the beam and a resonance frequency of the resonant cavity. The frequency of each beam is servo controlled to minimize the frequency difference observed. The laser beams are produced by a dual-frequency laser producing two beams of different frequencies and orthogonal polarizations. A polarization separator is used for separate servo control of the beams according to polarization, and a polarizer is placed behind a main output of the resonant cavity producing an electromagnetic beam mixing the two polarizations and amplitude-modulated at the beat frequency.

Abstract: The present invention relates to a light source control method capable of decreasing the dependence of a pulse width (FWHM) of an output pulsed light on a repetition frequency. A pulsed light source has an MOPA structure, and has a seed light source and an optical fiber amplifier. The seed light source includes a semiconductor laser which is directly modulated and outputs a pulsed light. By adjusting a temperature of the seed light source and a pumping light power of the optical fiber amplifier, a predetermined full width half maximum of a pulse at a predetermined repetition frequency is implemented for the pulsed light outputted from the optical fiber amplifier.

Abstract: Embodiments of the invention describe integrating a phase shifting component into a cavity of a laser. Said phase shifter is capable of a continuous phase shift at a single wavelength over a large range (where the maximum energy consumption of the phase shifting component does not scale with the phase shifting range). In other words, said phase shifter is used to form a configurable optical cavity length for a laser. Embodiments of the invention thus utilize a plurality of optical cavity lengths—including one or more optical cavity lengths to potentially shift the phase of the output optical signal, to maintain a laser cavity's output wavelength and avoid spatial mode-hops in the presence of fluctuations such as temperature drift or changes to the drive current of the laser.

Abstract: An RF power-supply for driving a carbon dioxide CO2 gas-discharge laser includes a plurality of power-oscillators phase-locked to a common reference oscillator. Outputs of the phase-locked power-oscillators are combined by a power combiner for delivery, via an impedance matching network, to discharge-electrodes of the laser. In one example the powers are analog power-oscillators. In another example, the power-oscillators are digital power-oscillators.

Abstract: A laser apparatus may include a master oscillator configured to output a laser beam, at least one amplifier disposed in a beam path of the laser beam from the master oscillator, at least one power source for applying a high-frequency voltage to the at least one amplifier, and a controller for varying the high-frequency voltage to be applied to the at least one amplifier from the at least one power source.

Abstract: A light source device is provided with a coherent light source for emitting the coherent light, and a pattern changer for changing an interference pattern of the coherent light on a surface of the illumination object. The pattern changer includes a photorefractive crystal which is arranged between the coherent light source and the illumination object and on an optical path of the coherent light and exhibits a photorefractive effect, and a changer for changing at least one of a light intensity distribution, a polarization direction, a wavelength and an intensity of coherent light incident on the photorefractive crystal. The illumination object is illuminated with the coherent light.

Abstract: There is provided a wavelength variable light source system capable of changing wavelength and intensity of output signal light and of improving preset accuracy and stability of the wavelength and strength of the output signal light. The system determines the both or either one of a target value for controlling wavelength and a target value for controlling intensity of output signal light of a wavelength variable light source by correlating a combination of the target wavelength and the target light output intensity specified from a higher-level device and controls operation states of the wavelength variable light source so that output values of monitoring circuits for monitoring the operation state of the wavelength variable light source converge to the target values.