Abstract: Embodiments are disclosed for driving a vertical cavity surface emitting laser (VCSEL). An example method includes injecting, via a universal driver, a direct current (DC) bias current to a VCSEL. The VCSEL is configured to convert the modulated signal into an optical signal encoding one or more bits. The example method further includes providing a modulated signal to the VCSEL. The modulated signal encodes a digital sequence comprising the one or more bits using a modulation method.

Abstract: A radiation source arrangement causes interaction between pump radiation (340) and a gaseous medium (406) to generate EUV or soft x-ray radiation by higher harmonic generation (HHG). The operating condition of the radiation source arrangement is monitored by detecting (420/430) third radiation (422) resulting from an interaction between condition sensing radiation and the medium. The condition sensing radiation (740) may be the same as the first radiation or it may be separately applied. The third radiation may be for example a portion of the condition sensing radiation that is reflected or scattered by a vacuum-gas boundary, or it may be lower harmonics of the HHG process, or fluorescence, or scattered. The sensor may include one or more image detectors so that spatial distribution of intensity and/or the angular distribution of the third radiation may be analyzed. Feedback control based on the determined operating condition stabilizes operation of the HHG source.

Abstract: An optically-monitored and/or optically-controlled electronic device is described. The device includes at least one of a semiconductor transistor or a semiconductor diode. An optical detector is configured to detect light emitted by the at least one of the semiconductor transistor or the semiconductor diode during operation. A signal processor is configured to communicate with the optical detector to receive information regarding the light detected. The signal processor is further configured to provide information concerning at least one of an electrical current flowing in, a temperature of, or a condition of the at least one of the semiconductor transistor or the semiconductor diode during operation.

Abstract: Technologies pertaining to accounting for pulse history effects are described herein. In connection with accounting for pulse history effects, an amount of time between a first current pulse and a second current pulse that are to be transmitted to a pulsed laser is determined. Based upon such an amount of time, a determination is made as to whether a porch pulse is to be prepended to the second current pulse. When the porch pulse is to be prepended to the second current pulse, an amplitude and duration of the porch pulse are computed based upon the amount of time. The porch pulse is transmitted to the pulsed laser immediately followed by the second current pulse, wherein the porch pulse pre-charges the pulsed laser for emitting a pulse of light based upon the second current pulse.

Abstract: A visual perception device has a look-up table stored in a laser driver chip. The look-up table includes relational gain data to compensate for brighter areas of a laser pattern wherein pixels are located more closely than areas where the pixels are further apart and to compensate for differences in intensity of individual pixels when the intensities of pixels are altered due to design characteristics of an eye piece.

Abstract: A laser system's laser light energy control and resulting dose control is improved by creating and using a set of gain estimators, one for each of a set or range of laser light pulse repetition rates. When a new repetition rate is used, its corresponding gain estimator is retrieved, used to compute the voltage to fire the laser source, and updated. The resulting generated laser light thereby avoids the convergence delay inherent in prior laser systems and, further, can repeatedly do so with subsequent specified repetition rates.

Abstract: An electronic apparatus includes an airflow generation device and a passive component. The passive component is a temperature sensor and includes a component body and a heat sink attached to the component body. The heat sink can absorb environmental heat which is dissipated through the air flow. The airflow generation device operates according to a sensing result by the passive component.

Abstract: An LD driver circuit includes an adjustment circuit to which a power supply voltage is applied. The adjustment circuit receives an input signal through an input terminal, generates a shifted input signal shifted in voltage from the input signal by a predetermined shift amount, and outputs the shifted input signal from an output terminal. The LD driver circuit also includes a transistor with its base receiving the shifted input signal, its collector electrically connected to an anode of a driven LD, and its emitter electrically connected to a cathode of the LD and ground, which transistor varies an amount of a shunt current flowing from the collector to the emitter in accordance with the shifted input signal. The adjustment circuit includes a comparator which compares a voltage in the collector and a threshold voltage, and increases or decreases the predetermined shift amount in accordance with an output of the comparator.

Abstract: A cylindrical package includes a cylindrical housing; a pedestal at a bottom of a cylindrical space surrounded by the cylindrical housing; an optical splitter in the cylindrical space and over the pedestal; a first photodetector in the cylindrical space and over the pedestal, wherein the first photodetector is configured to be optically coupled to the optical splitter; and a second photodetector in the cylindrical space and over the pedestal, wherein the second photodetector is configured to be optically coupled to the optical splitter.

Abstract: An image drawing device includes a laser light source controller controlling a laser light output timing of a laser light source unit and an output value of laser light so that a drawing image based on input image data is generated in a scanning region; a scanner controller controlling scanning so that the laser light is scanned with an amplitude; and a characteristic detection controller controlling the scanner controller to scan in a range in which an amplitude of scanning exceeds a scanning range corresponding to an amplitude when the laser light output value is adjusted, control the laser light source controller to output characteristic detection laser light during scanning outside of a range in which the drawing image is generated and beyond the amplitude of the scanning range, and adjust the output value of the laser light based on a detected output value of the characteristic detection laser light.

Abstract: An optical transceiver includes an optical transmitter and an optical receiver. The optical transmitter includes a laser diode configured to convert a current signal into an optical signal; a main driver comprising first and second output terminals that have a differential structure, the main driver configured to drive the first and second output terminals in response to differential input signals and to provide the current signal to the laser diode through the first output terminal; and an impedance balancer configured to match impedances of the first and second output terminals by adjusting the impedance of the second output terminal according to signal states of the first and second output terminals.

Abstract: An apparatus comprises a laser diode configured to generate modulated light during a write operation in response to receiving modulated current having a mean amplitude that varies or is constant. A slider is configured for heat-assisted magnetic recording and to receive the modulated light. A writer heater of the slider is configured to receive power during the write operation having a magnitude that varies or is constant. A sensor is situated on or within the slider. The sensor is configured to produce a sensor signal representative of output optical power of the laser diode. Measuring circuitry is coupled to the sensor and configured to measure a change in the sensor signal indicative of a laser mode hop during the write operation.

Abstract: A laser device suppresses the variation of each time-lag so that a distortion of a combined laser output is suppressed. The laser device includes electric current control elements Q1, Q2 connected in series to a laser diode unit corresponding to respective laser diode units LD1, LD2, an electric current control circuit 11 that controls an electric current flow in the laser diode unit by adding a voltage to a control terminal of the electric current control element to turn on the electric current control element, and voltage adjustment circuits 12a, 12b corresponding to the laser diode unit adjusts, individually, every laser diode unit and the voltage that is added to the control terminal of the electric current control element when the laser diode is off.

Abstract: A system and method for detecting hard targets in a free-space laser system includes a laser, an optical detector, and electronics. The laser is configured to emit a laser beam along an optical path through transmitter optics into a field of view. The optical detector is positioned along a laser transmitter path and configured to receive retroreflections of the laser beam. The electronics are configured to determine if an output of the optical detector is indicative of presence of a hard target within the field of view, and control the laser to a safe state if the output is indicative of presence of the hard target.

Abstract: An optical module and a method of assembling the optical module are disclosed. The optical module comprises a laser unit, a modulator unit, and a detector unit mounted on respective thermo-electric coolers (TECs). The modulator unit, which is arranged on an optical axis of the first output port from which a modulated beam is output, modulates the continuous wave (CW) beam output from the laser unit. On the other hand, the laser unit and the detector unit are arranged on another optical axis of the second output port from which another CW beam is output. The method of assembling the optical module first aligns one of the first combination of the laser unit and the modulator unit with the first output port and the second combination of the laser unit and the detector unit, and then aligns another of the first combination and the second combination.

Abstract: Gain switched laser diode pulses are used as seed pulses for optical pulse generation. ASE is reduced by applying a prebias to the laser diodes at an amplitude less than that associated with a laser diode threshold. An electrical seed pulse having an amplitude larger than that associated with laser threshold is applied within about 10-100 ns of the prebias pulse. The resulting laser diode pulse can be amplified in a pumped, rare earth doped optical fiber, with reduced ASE.

Abstract: A method of controlling a wavelength tunable laser to control an oscillation wavelength based on a difference between a detection result of a wavelength by a wavelength detecting unit and a target value, the method includes: acquiring a first drive condition of the wavelength tunable laser to make the wavelength tunable laser oscillate at a first wavelength from a memory; calculating a second drive condition to drive the wavelength tunable laser at a second wavelength by referring to the first drive condition and a wavelength difference between the first wavelength and the second wavelength, the second wavelength differing from the first wavelength; and driving the wavelength tunable laser based on the second drive condition calculated at the calculating of the second drive condition.

Abstract: An LED lighting system is disclosed comprising: a heatsink; a plurality of strings of LEDs each string comprising one or more LEDs each having a junction and being mounted on the heatsink, and a controller comprising a memory unit and a processor and being configured to supply a current to each of the strings of LEDs; the processor comprises: a first temperature estimation subunit configured to generate an estimate of a temperature of the junction of a one of strings of LEDs; a heatsink temperature estimation subunit configured to estimate a temperature of the heatsink unit from the first estimate; and a second temperature estimation subunit configured to provide an estimate of a temperature of the junction of a second string of LEDs, from the estimated temperature of the heatsink. A controller for and method of operating a plurality of LEDs are also disclosed.

Abstract: A circuit arrangement for operating a laser diode in clocked mode includes a monitor photodiode, from the signal of which a measure of the radiation emitted by the laser diode is obtained as voltage to be measured, and a comparator, which compares the voltage to be measured with a reference voltage and provides the difference signal to a controller, wherein both the voltage to be measured and the reference voltage are applied continuously to the comparator. In order to carry out operation of the laser diode in clocked mode, a clocked-mode operation of the energy supply of the comparator is provided.

Abstract: The invention is a method and apparatus to provide a temperature compensation for LED brightness utilizing temperature dependence of voltage-current characteristic of the LED. Methods ensure the precise compensation of brightness of LED using two or more temperatures to tune an LED driver circuit without the use of thermistors or other temperature sensor. This method also allows for circuits that compensate brightness not only of a single LED but of an assembly of LEDs. The method allows to manufacture LED modules with built-in temperature brightness compensation circuit. These modules can be used in a variety of illuminating equipment including but not limited to home lights, vehicle turn or brake signals, traffic lights, and a backlight for LCD display.

Abstract: An image forming apparatus is provided for controlling current(s) supplied to a semiconductor laser. In one or more embodiments, an image forming apparatus corrects a value of the driving current and a value of at least one correction current (e.g., first and/or second correction current(s)) supplied in synchronization with the supply start of the driving current based on a reception result of a light receiving unit. In one or more embodiments, an image forming apparatus includes a correction current supply unit including a first correction current generation unit for generating a first correction current that attenuates over time and a second correction current generation unit for generating a second correction current that attenuates over time and of which an attenuation speed is lower than that of the first correction current, and configured to supply the first correction current and the second correction current to the semiconductor laser.

Abstract: An optical network terminal with functions of detecting, recovering and blocking failures, and storing the information according to the present invention comprises: an uplink carrying out a function to communicate with a high level system; a communication port distributing or integrating the communication; a CPU managing distribution and integration of the communication; and a system power source for supplying power to the uplink, the communication port and the CPU, wherein the uplink comprises an optical module carrying out optical communication with the high level system; a MAC module controlling optical communication with the high level system; and a failure detection, recovery and blocking module for detecting optical output of the optical module, recovering failures and blocking optical output outside the MAC module. In accordance with the present invention, faster and specific failure solution can be provided using a low-cost microprocessor and its storage media.

Abstract: Various embodiments of a coherent receiver including a widely tunable local oscillator laser are described herein. In some embodiments, the coherent receiver can be integrated with waveguides, optical splitters and detectors to form a monolithic optical hetero/homodyne receiver. In some embodiments, the coherent receiver can demodulate the full phase information in two polarizations of a received optical signal over a range of optical wavelengths.

Abstract: A method and apparatus of generating a laser pulse of a desired energy and micro-machining a substrate using the laser pulse. A beam of light is provided from a laser source. The beam is directed via a modulator to produce an output laser pulse with a portion of the laser pulse being used to determine the energy of the laser pulse. The modulator is controlled so as to switch off the output laser pulse when the determined energy of the output laser pulse reaches a threshold value. The output laser pulse is steered to a substrate for micro-machining.

Abstract: A laser apparatus includes a master oscillator capable of outputting a laser beam having a spectrum that includes at least three wavelength peaks, a multi-wavelength oscillation control mechanism capable of controlling energy of each of the wavelength peaks, a spectrum detecting unit that detects the spectrum of the above-mentioned laser beam, and a controller that controls the multi-wavelength oscillation control mechanism based on a detection result detected by the spectrum detecting unit.

Abstract: A laser diode (LD) driver to suppress the excess emission of an LD is disclosed. The LD driver has the shunt configuration with a driving transistor connected in parallel to the LD to shunt the bias current provided to the LD. The driver further provides a protection circuit to divide the bias current when the bias current is active but the driving transistor is turned off at an instant of the power on and off of the LD driver.

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: There is provided a light source including a mode-lock laser unit that includes a semiconductor laser and an external resonator unit and emits a laser beam having a predetermined frequency, the semiconductor laser including a saturable absorber unit that applies a reverse bias voltage and a gain unit that applies a gain current, a semiconductor optical amplifier that performs amplification modulation on the laser beam emitted from the mode-lock laser unit, a laser clock generating unit that generates a laser clock synchronized with the laser beam based on a signal detected from the saturable absorber unit when the laser beam oscillates in the mode-lock laser unit, and a modulating unit that generates a driving current synchronized with the laser clock and applies the driving current to the semiconductor optical amplifier.

Abstract: In one embodiment of the invention, a semiconductor optical amplifier (SOA) in a laser ring is chosen to provide low polarization-dependent gain (PDG) and a booster semiconductor optical amplifier, outside of the ring, is chosen to provide high polarization-dependent gain. The use of a semiconductor optical amplifier with low polarization-dependent gain nearly eliminates variations in the polarization state of the light at the output of the laser, but does not eliminate the intra-sweep variations in the polarization state at the output of the laser, which can degrade the performance of the SS-OCT system.

Abstract: A laser apparatus and bio-imaging apparatus are provided, which include: a mode-lock laser unit including a saturable absorber section that applies a bias voltage, a gain section that feeds a gain current, a semiconductor laser that emits laser light, and an external resonator; an optical modulation unit performing amplification modulation on the laser light emitted from the mode-lock laser unit; a reference signal generation unit generating a master clock signal and supplying a signal synchronized with the master clock signal to the gain section of the semiconductor laser; and a driving circuit generating a driving pulse used to drive the optical modulation unit based on the reference signal.

Abstract: An optical module providing higher reliability during high-speed light modulation and a lower bit error rate when built into a transmitter (transceiver). An optical module contains a taper mirror for surface emission of output light, an optical modulator device, and an optical modulation drive circuit, and the optical modulator device and the optical modulation drive circuit are mounted at positions so as to enclose the taper mirror.

Abstract: A method for adjusting laser beams (4) for scanners arranged on a support for radiotherapy, by a device consisting of a one-piece assembly (1) comprising (3) a suitable electronic control board (8), and position sensors (3) for visualizing the position of the beams (4), and adjusting them automatically by motor-driven systems, which is remarkable in that it comprises the steps of installing the apparatus (1); presetting of the position via 3 support feet (6) and embedded spirit levels (7); movement of the table of the scanner to position the front face (11) of the apparatus in the plane of the isocenter of the scanner and positioning via internal lasers of the scanner; acquisition of position control images of the apparatus (1) and finalization and validation thereof, movement of the table of the scanner by the nominal distance between the machine isocenter and the laser isocenter, which is determined and validated at the time of installation of the lasers; connection of the apparatus (1) and powering up ther

Abstract: A laser system may include: a master oscillator configured to output pulsed laser light; an amplification device for amplifying the pulsed laser light from the master oscillator; a first timing detector configured to detect a first timing at which the master oscillator outputs the pulsed laser light; a second timing detector configured to detect a second timing at which the amplification device discharges; and a controller configured to, based on results of detection by the first timing detector and the second timing detector, control at least one of the first timing and the second timing so that the amplification device discharges when the pulsed laser light passes through a discharge space of the amplification device.

Abstract: A method or algorithm to control a driving current supplied to a semiconductor laser diode (LD) is disclosed. the method first prepares the look-up-table (LUT) that stores a set of parameters, ? and ?, for evaluating the modulation current Im by the equation of Im=?×Ib+?, where Ib is determined by the auto-power-control (APC) loop. In a practical operation of the LD, the APC loop determines Ib, while, Im is calculated according to the equation above by reading above two parameters corresponding to the current temperature of the LD from the LUT.

Abstract: Apparatus and systems create differential drive signals suitable for HAMR data recording. A laser diode differential driver provides heating current pulses at a time ?1. The pulses energize a laser diode to pre-heat the magnetic medium to be written. Some embodiments duplicate portions of the laser diode circuit architecture to create a magnetic write head differential driver. The write head driver provides write current pulses to a magnetic write head in one direction with ?1 timing and in the opposite direction with ?2 timing. Both drivers utilize sets of reference voltages capable of being switched to one terminal or the other of the element to be driven. In the laser diode case, the common mode is split between the anode and cathode sections of the driver. A feedback element is added between the cathode and anode sections to provide current accuracy independent of the electrical characteristics of the selected laser diode.

Abstract: According to one embodiment, a solid state lighting device includes an irradiating section, a scattering section, a wavelength conversion layer, a supporting plate, a returned light guiding section, a light receiving section, and a control circuit. The irradiating section emits laser light. The scattering section includes a light scattering material that reflects the laser light and emits the laser light as scattered light. The wavelength conversion layer absorbs the scattered light made incident thereon and emits wavelength-converted light. The scattered light and the wavelength-converted light change to returned light and propagate through the inside of the supporting plate. The returned light is introduced into the returned light guiding section. The light receiving section detects the returned light. When a detected light amount of the returned light is outside a predetermined range, the control circuit outputs an emission stop signal for the laser light to the irradiating section.

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: 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: A laser diode driving apparatus for optical communication is provided so as to prepare a low-price and low-power optical transmission and reception apparatus by realizing the high performance laser diode driving apparatus for optical communication with a structure appropriate for a multichannel array that can easily and effectively provide stable bandwidths and high gains of the optical communication laser diode at a transmission end of the optical transmission and reception apparatus.

Abstract: A method for monitoring a laser system including a plurality of laser modules connected in series, there being connected in parallel to each laser module a bypass arrangement for bridging the corresponding laser module, includes determining a first laser power of the laser system with a plurality of laser modules operational; activating the bypass arrangement of at least one laser module so that at least one of the plurality of laser modules is bypassed; determining a second laser power of the laser system with the at least one of the plurality of laser modules bypassed; and monitoring the laser system based on a difference between the first and second laser power.

Abstract: A laser processing apparatus, a filter device and a method are used for controlling a pulse laser, which is controllable in terms of its pulse energy and of a temporal triggering of laser pulses, during material processing of an object, in particular during the marking of a plastics-based document. The method includes comparing a pulse energy signal which assumes voltage values, in temporal correlation with a clock signal, which represent a pulse energy for the laser pulses for processing, with a threshold value condition and generating a logic result signal. The clock signal is passed to a gate and controlling the gate using the logic result signal and generating a retrieval signal thereby. An energy control signal is provided which has a voltage according to a specification of a control voltage. The retrieval signal and the energy control signal are used to control the pulse laser.

Abstract: A method and apparatus for stabilizing the seed laser in a laser produced plasma (LPP) extreme ultraviolet (EUV) light system are disclosed. In one embodiment, the cavity length of the laser may be adjusted by means of a movable mirror forming one end of the cavity. The time delay from the release of an output pulse to the lasing threshold next being reached is measured at different mirror positions, and a mirror position selected which results in a cavity mode being aligned with the gain peak of the laser, thus producing a minimum time delay from an output pulse of the laser to the next lasing threshold. A Q-switch in the laser allows for pre-lasing and thus jitter-free timing of output pulses. Feedback loops keep the laser output at maximum gain and efficiency, and the attenuation and timing at a desired operating point.

Abstract: A thin beam laser crystallization apparatus for selectively melting a film deposited on a substrate is disclosed having a laser source producing a pulsed laser output beam, the source having an oscillator comprising a convex reflector and a piano output coupler; and an optical arrangement focusing the beam in a first axis and spatially expanding the beam in a second axis to produce a line beam for interaction with the film.

Abstract: A laser system includes an array of lasers that emit light at a number of different, fixed wavelengths. A group of optical transport systems connect to the laser system. Each of the optical transport systems is configured to modulate data signals onto the light from the laser system to create optical signals and transmit the optical signals on one or more optical fibers.

Abstract: Embodiments for driving a laser diode includes generating a bias current having a duty cycle that is less than 100%. The current level of the bias current is insufficient to turn on the laser diode. A drive current is generated and combined with the bias current to turn on the laser diode almost instantly.

Abstract: A laser emitter module may include a first laser emitter configured to output first laser beam having a first radiation angle by receiving first input laser beam and a second laser emitter configured to output second laser beam having a radiation angle different from the first radiation angle by receiving second input laser beam having a width different from that of the first input laser beam. The first and second laser emitters output the first and second laser beam together.

Abstract: An improved ignition safety device (ISD) employs one or more optical switches to accomplish a SAFE-ARM function for a laser initiated ordnance system (LIOS). At least one optical switch along with appropriate control and status monitoring provide an optical SAFE-ARM function and optionally a distribution function. An optical switch performing the SAFE-ARM function diverts a laser signal to a heat sink assembly when in a SAFED position and switches to the LIOS when in an ARMED position. When in the SAFED position, the LOSAD provides an optical block in the laser energy path between a laser firing unit and the LIOS to prevent inadvertent ordnance operation. An optical switch performing the distribution function has two or more switch positions that direct a received laser signal to two or more laser initiated devices.

Abstract: A source of light that could cause ocular damage within a given range from the source of light, such as a first laser, is accompanied by an optical hazard avoidance device, such as a second laser, that stimulates voluntary, involuntary, or both voluntary and involuntary responses, either physiological or behavioral or both physiological and behavioral, within one or more hazard zones, such as by inducing gaze aversion within the viewer. For example, a visible laser beam induces gaze aversion, pupil contraction or a combination of gaze aversion and pupil contraction, reducing the dose rate or exposure of the ocular tissue to damaging radiation from a primary source. In one example, the primary source is a UV Raman detector and the visible laser beam is selected to induce gaze aversion.

Abstract: The present invention is directed to a laser system in which a current laser wavefront performance of the laser system may be monitored. Further, the laser system embodiments disclosed herein may be configured for correcting the laser wavefront internally via correction system(s) within the laser system. Still further, the correction system(s) disclosed herein may provide a long lifetime of performance and may be configured for having a minimal impact on photocontamination.

Abstract: The present invention relates to opto-isolators. Opto-isolators are disclosed that include a transmitter package and a vertical VCSEL disposed within the transmitter package. The opto-isolators further include a receiver package and a photodetector disposed within the receiver package. The photodetector is optically coupled to the VCSEL and configured to receive an output optical signal generated by the VCSEL. The opto-isolators further include an alignment package configured to receive the transmitter package and the receiver package. In another embodiment, opto-isolators include a VCSEL and a photodetector optically coupled to the VCSEL and configured to receive an output optical signal generated by the VCSEL. The opto-isolators further include a package enclosing both the VCSEL and the photodetector.