Abstract: A semiconductor laser excited solid state laser device and method. The device including a semiconductor laser; a driving device; a solid state laser module which has maximum output efficiency at the set temperature and which generates, from excitation light, an output light of a predetermined output level when the optical noise is at or below a fixed level and the output level of the excitation light is the set output level; a single temperature adjustment device which adjusts the temperature of the semiconductor laser and the temperature of the solid state laser module; and a control device which controls the driving device such that the output light will be at the predetermined output level and controls the temperature adjustment device such that the temperature of the semiconductor laser and the solid state laser module will be the set temperature.

Abstract: A laser device 1 demultiplexes seed light L0 into a plurality of beams of laser light L1 and then continuously optically amplifies the plurality of beams of the laser light L1 with an amplifier 14. Therefore, its amplification factor can be set higher than that in the case of amplifying pulsed laser light. When producing multiplexed light L3 by multiplexing the beams of the amplified laser light L1 with a diffraction grating 16, respective phases of the beams of the laser light L1 are controlled such that an output peak of the multiplexed light L3 repeatedly appears at a converging position P1 at a predetermined time interval. This produces pulsed laser light at the converging position P1 from a plurality of beams of laser light L2 amplified at a high amplification factor. Hence, this laser device 1 can produce pulsed laser light with a high output.

Abstract: In a method for operating a laser system in a Q-switched mode, the laser system provided with a laser resonator with a laser medium and an electro-optical modulator, wherein the electro-optical modulator has an EOM crystal, wherein the EOM crystal has a characteristic ringing time (t0) when subjected to acoustic ringing, the EOM crystal is driven by modulator voltage pulses (pm) having a modulator voltage pulse duration (tml). A train of at least two subsequent laser pulses (pl) is generated. The modulator voltage pulse duration (tml) is selected to be at least approximately equal to the characteristic ringing time (t0) of the EOM crystal multiplied by an integer factor.

Abstract: A peak value detector detects power of an output light pulse which is output from the light amplifying fiber. A light receiving element receives a group of light pulses including a plurality of pulses and converts the group of light pulses into a current signal. The current/voltage converter circuit converts the current output from the light receiving element to voltage. The integration circuit integrates the voltage output from the current/voltage converter circuit. A programmable gain amplifier (PGA) amplifies the signal output from the integration circuit and provides the signal for the A/D converter circuit. The gain of the PGA is set by a gain setting signal from the signal processing circuit. The signal processing circuit adjusts the gain of the PGA so that the gain increases as the repetition frequency of the group of pulses increases.

Abstract: High power parallel fiber arrays for the amplification of high peak power pulses are described. Fiber arrays based on individual fiber amplifiers as well as fiber arrays based on multi-core fibers can be implemented. The optical phase between the individual fiber amplifier elements of the fiber array is measured and controlled using a variety of phase detection and compensation techniques. High power fiber array amplifiers can be used for EUV and X-ray generation as well as pumping of parametric amplifiers.

Abstract: Systems and methods of optical parametric chirped pulse amplification for laser pulses are provided. Techniques and components include replacing pulse stretcher and/or pulse compressors with chirped volume Bragg gratings (CVBGs) to reduce size, weight, cost, and environmental sensitivity of the laser system.

Abstract: Methods and apparatus for the active control of a wavelength-swept light source used to interrogate optical elements having characteristic wavelengths distributed across a wavelength range are provided.

Abstract: A method of tuning the time duration of laser output pulses, the method including spectrally dispersing optical pulses and further comprising providing an optical pulse having a time duration and a spectral bandwidth; spectrally dispersing (243, 245) the optical pulse so as to provide a selected change in the time duration of the pulse responsive to the spectral bandwidth of the pulse; outputting (226) an optical output pulse having a first time duration that is responsive to the selected change in time duration; providing another optical pulse; changing the amount of spectral bandwidth of the another optical pulse (272) to be different than that of the optical pulse or changing the amount of spectral dispersion so that spectrally dispersing the another optical pulse provides a change in time duration that is different than the selected change; and outputting (226) another optical output pulse having a second time duration that is responsive to the different change in time duration, the second time duration o

Abstract: An optical pulse output apparatus and method for controlling a width and an intensity of an optical pulse are provided. The optical pulse output apparatus may include a laser driver to control an optical pulse output by a laser, based on a plurality of channel signals, and a channel delay unit to delay at least one of the plurality of channel signals.

Abstract: An ultrashort pulse laser processing apparatus for processing a processing target includes: a laser head which includes a seed laser source emitting an ultrashort pulse seed laser, and emits a laser pulse; an optical fiber which guides the laser pulse emitted from the laser head; and an emission end unit which includes a compressor that compresses the laser pulse emitted from the optical fiber to a laser pulse of a predetermined high peak power and emits the laser pulse compressed by the compressor to the target.

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: An inexpensive pulse laser device that outputs a laser pulse capable of welding a transparent member is provided. There is provided a pulse laser device including: a laser light source 1 that outputs a repeated pulse laser; a demultiplexer 2 that demultiplexes the pulse laser output from the laser light source 1 into two pulse lasers; first pulse train generation means 3 that generates a first pulse train by changing at least a peak power and/or a pulse width of one of the two pulse lasers demultiplexed by the demultiplexer 2; and a multiplexer 4 that multiplexes the other of the two pulse lasers demultiplexed by the demultiplexer 2 and the first pulse train generated by the first pulse train generation means 3, in which a pulse laser in which a low-peak power pulse laser is superimposed on a high-peak power ultra-short pulse laser is output.

Abstract: Designs and techniques for constructing and operating femtosecond pulse lasers are provided. One example of a laser engine includes an oscillator that generates and outputs a beam of femtosecond seed pulses, a stretcher-compressor that stretches a duration of the seed pulses, and an amplifier that receives the stretched seed pulses, amplifies an amplitude of selected stretched seed pulses to create amplified stretched pulses, and outputs a laser beam of amplified stretched pulses back to the stretcher-compressor that compresses their duration and outputs a laser beam of femtosecond pulses. The amplifier includes a dispersion controller that compensates a dispersion of the amplified stretched pulses, making the repetition rate of the laser adjustable between procedures or according to the speed of scanning. The laser engine can be compact with a total optical path of less than 500 meters, and have a low number of optical elements, e.g. less than 50.

Abstract: The present invention relates to a high-power femtosecond pulsed laser, the laser including: a source able to generate a train of input laser pulses having an envelope frequency and a carrier frequency; a chirped pulse amplification unit; and, a unit for controlling the phase drift between the envelope frequency and the carrier frequency of the output laser pulses. According to the invention, the unit for controlling the phase drift between the envelope frequency and the carrier frequency includes electro-optical phase-modulation unit that are placed on an optical path of the chirped pulse amplification unit in order to stabilize the phase drift between the envelope frequency and the carrier frequency of the output laser pulses as a function of time.

Abstract: A method and apparatus are operative to control the desired level of population inversion in a gain medium having an amplified spontaneous emission (ASE) spectrum which is characterized by distinct short- and long-wavelength regions. The control is realized by the apparatus configured to determine a relationship between the regions of the ASE spectrum represented by respective frequencies which are filtered by respective frequency discriminators. The apparatus includes a controller operative to process the filtered frequencies by determining a relationship between amplitudes of the respective filtered frequencies which represents a measured level of population inversion. Upon mismatch between the measured level and desired level of the population inversion, a control signal is coupled into a pulse generator or pump or both. In response, the pulse generator may output a pulse, or/and the pump may be completely shut down to lower the level of the measured inversion.

Abstract: A laser device 1 demultiplexes seed light L0 into a plurality of beams of laser light L1 and then continuously optically amplifies the plurality of beams of the laser light L1 with an amplifier 14. Therefore, its amplification factor can be set higher than that in the case of amplifying pulsed laser light. When producing multiplexed light L3 by multiplexing the beams of the amplified laser light L1 with a diffraction grating 16, respective phases of the beams of the laser light L1 are controlled such that an output peak of the multiplexed light L3 repeatedly appears at a converging position P1 at a predetermined time interval. This produces pulsed laser light at the converging position P1 from a plurality of beams of laser light L2 amplified at a high amplification factor. Hence, this laser device 1 can produce pulsed laser light with a high output.

Abstract: A system for generating a shaped optical pulse is disclosed. The system includes a master oscillator for generating an initial optical pulse, which is then directed to a semiconductor optical amplifier to amplify a portion of the initial optical pulse. The amplified pulse is reflected from a fiber Bragg grating to spectrally clean the amplified pulse and the reflected portion is returned back through the semiconductor optical amplifier. The semiconductor optical amplifier is activated a second time to amplify the reflected portion of the pulse. The time delay between the two activations of the semiconductor optical amplifier is selected to generate an output pulse with desired duration and/or amplitude profile over time.

Abstract: Apparatus, systems, and methods of generating multi combs can be used in a variety of applications. In various embodiments, an etalon can be disposed in the laser cavity of a mode-locked laser to adjust frequency combs. Additional apparatus, systems, and methods are disclosed.

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: Methods and apparatuses for generating microscopic patterns of macromolecules such as proteins on a solid surface are described. Pulsed laser light is used to alter surface portions of a solid surface substrate in a predetermined pattern, by removing macromolecules from surface portions of the substrate where the light is focused. The same wavelength light at lower intensity can be used to visualize the removal by its reflection from the specimen surface along the path to the detector. Select macromolecules introduced to the substrate selectively adhere to select surface portions, thereby depositing macromolecules in the predetermined pattern on the solid surface.

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: A method to tune an emission wavelength of a wavelength tunable LD is disclosed. The wavelength tunable LD includes two regions each providing micro heaters to modify the refractive index of micro regions provided with power. The method periodically detects a difference between the emission wavelength and the target wavelength. This wavelength difference is converted into power next supplied to respective micro heaters independently.

Abstract: A degree of polarization control device includes: a calcium fluoride crystal substrate for transmitting a laser beam; a polarization monitor for measuring the degree of polarization of a laser beam transmitted through the calcium fluoride crystal substrate; and a controller for controlling the rotation angle of the calcium fluoride crystal substrate according to the degree of polarization measured by the polarization monitor; the calcium fluoride crystal substrate being formed by a flat plate having a laser beam entering surface and a laser beam exiting surface running in parallel with the (111) crystal face, the Brewster angle being selected for the incident angle, the rotation angle around the [111] axis operating as a central axis being controlled by the controller.

Abstract: A laser apparatus may include a master oscillator configured to output a laser beam, at least one amplifier provided in a beam path of the laser beam, at least one saturable absorber gas cell provided downstream from the at least one amplifier and configured to contain a saturable absorber gas for absorbing a part of the laser beam, the part having a beam intensity equal to or lower than a predetermined beam intensity, and a cooling unit for cooling the saturable absorber gas.

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: The pulse light source comprises a semiconductor laser outputting pulse light, an optical filter, and an optical amplifier. The optical filter outputs a chirping component of the inputted pulse light, by adjusting a relative position of a transmission spectrum of the optical filter with respect to an output spectrum of the seed light source.

Abstract: There is disclosed a femtosecond laser apparatus including a first laser material comprising Ng, Np and Nm axes spatially perpendicular to each other; a second laser material comprising Np axis, Nm axis and Ng axis; and a first laser diode and second laser diodes, wherein the traveling direction of laser beams generated from the first and second laser materials is substantially parallel to Ng axis of the first laser material and the polarizing direction of laser beams generated from the first and second laser materials is substantially parallel to Np axis of the first laser material, and the traveling direction of laser beams generated from the first and second laser materials is substantially parallel to Np axis of the second material and the polarizing direction of laser beams generated from the first and second laser materials is substantially parallel to Nm axis of the second laser material.

Abstract: A laser apparatus may include a seed laser device configured to output a pulse laser beam, a pulse energy adjusting unit configured to vary pulse energy of the pulse laser beam, at least one amplifier for amplifying the pulse laser beam, at least one power source for varying an excitation intensity in the at least one amplifier, and a controller configured to control the pulse energy adjusting unit on a pulse-to-pulse basis for the pulse laser beam passing therethrough and to control the at least one power source for a group of multiple pulses of the pulse laser beam.

Abstract: The present invention relates to a method of processing a metal thin film formed on a transparent substrate by radiating pulsed light onto the metal thin film, and having the steps of repeatedly outputting the pulsed light by directly modulating a semiconductor laser of the seed light source in accordance with electric signals, amplifying the pulsed light using an optical amplifier including an optical amplification medium, controlling the full width at half maximum of the pulsed light that is amplified and outputted by the optical amplifier to be 0.5 ns or less, and removing the metal thin film by radiating the pulsed light thus having the controlled full width at half maximum onto the metal thin film through the transparent substrate.

Abstract: A modular ultrafast pulse laser system is constructed of individually pre-tested components manufactured as modules. The individual modules include an oscillator, pre-amplifier and power amplifier stages, a non-linear amplifier, and a stretcher and compressor. The individual modules can typically be connected by means of simple fiber splices.

Abstract: A high peak intensity laser amplification system and the method therein implemented are provided. In a first aspect of the invention, the laser system includes at least one optical member (27) operably introducing a phase function into a high peak intensity laser pulse (25). A further aspect includes introducing destructive interference in an unchirped laser pulse prior to amplification and reconstructive interference in the output laser pulse after amplification. Dynamic pulse shaping is employed in another aspect of the present invention.

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 tiled Bragg grating (BG) includes a plurality of BGs that are paralleled and optically contacted to one another. Each BG includes an optically transparent substrate within a predetermined wavelength or wavelength range having a length dimension and a transverse dimension. The BGs have a grating period along their length dimension. The BGs have optical contact regions along edges in their transverse dimension where the BGs are optically contacted to one another.

Abstract: The invention describes classes of robust fiber laser systems usable as pulse sources for Nd: or Yb: based regenerative amplifiers intended for industrial settings. The invention modifies adapts and incorporates several recent advances in FCPA systems to use as the input source for this new class of regenerative amplifier.

Abstract: A master oscillator power amplifier (MOPA) system includes an oscillator having a neodymium-doped gadolinium vanadate gain-medium and delivering seed-pulses. A length of single mode fiber is used to broaden the spectrum of the seed pulse. An amplifier having a neodymium-doped yttrium vanadate gain-medium amplifies the spectrally broadened seed-pulses. The gain-spectrum of the amplifier partially overlaps the broadened pulse-spectrum, providing spectral selection of the seed-pulses in addition to amplification. This provides amplified output-pulses having a duration about one-third that of the corresponding seed-pulses.

Abstract: The present invention relates to a laser apparatus for inducing a photo-mechanical effect. More particularly, the present invention relates to a laser apparatus for outputting a pulsed laser beam and inducing a photo-mechanical effect by controlling pulse energy of the pulsed laser beam.

Abstract: An apparatus and method for enhancing pulse contrast ratios for drive lasers and electron accelerators. The invention comprises a mechanical dual-shutter system wherein the shutters are placed sequentially in series in a laser beam path. Each shutter of the dual shutter system has an individually operated trigger for opening and closing the shutter. As the triggers are operated individually, the delay between opening and closing first shutter and opening and closing the second shutter is variable providing for variable differential time windows and enhancement of pulse contrast ratio.

Abstract: Processes such as annealing amorphous silicon to form polysilicon use exposures to pulsed laser beams provided by laser diodes or arrays of laser diodes. An optical beam based on plurality of beams from respective laser diodes is shaped and directed to a substrate. Duty cycles of the laser diodes are selected to be less than about 0.2, so that °s can be greater than available in continuous wave operation. An amorphous silicon layer on a rigid or flexible substrate is processed to produce a polysilicon layer with a mobility of at least 50 cm2/Vs.

Abstract: A laser system includes a seed laser configured to generate a plurality of optical pulses; a controller configured to receive the plurality of the optical pulses and obtain chirped pulses, each chirped pulse having a chirping amount different from each other; an optical waveguide, having a characteristic of anomalous dispersion, configured to cause soliton self-frequency shifts while the chirped pulses propagating so that each center wavelength of a pulse which output from the optical waveguide is different from each other.

Abstract: Pulse power can be stabilized by applying spectrally narrow pulses to a laser diode during gain switching. An injection locking laser with a narrow emission bandwidth is tuned to a gain bandwidth of a laser diode to be gain switched. The injection locking emission is pulsed to provide locking pulses that are attenuated and then coupled to a laser diode. A gain switching pulse drive is applied to the laser diode in the presence of the attenuated locking pulses. The gain switched output is then stabilized with respect to pulse energy and pulse amplitude, and is suitable as a seed pulse for lasers to be used in materials processing.

Abstract: An apparatus includes a light source that produces a light beam, a bandwidth measurement system, a plurality of bandwidth actuation systems, and a control system. Each bandwidth actuation system includes one or more bandwidth actuators and each bandwidth actuation system is connected to an optical feature that is optically coupled to the produced light beam and operable to modify the connected optical feature to select a bandwidth within a bandwidth range of the produced light beam. The control system is connected to the bandwidth measurement system and to the plurality of bandwidth actuation systems. The control system is configured to switch between activating and operating a first bandwidth actuation system and activating and operating a second bandwidth actuation system independently and separately of activating and operating the first bandwidth actuation system based on a provided bandwidth measurement and a selected target bandwidth.

Abstract: A chirped-pulsed amplification laser device includes a fiber laser driver, a laser head, and a delivery fiber that guides amplified stretched laser pulses from the laser driver to the laser head. The fiber laser driver includes a seed pulsed laser, a pulse stretcher, and an optical power amplifier. A chirped fiber Bragg grating compressor in the laser head includes a fiber terminal section configured to minimize broadening of the amplified stretched laser pulses, a chirped fiber Bragg grating section connected to the fiber terminal section and configured to compress and reflect amplified stretched laser pulses to produce reflected laser pulses with compressed pulse durations, and a collimator housing configured to fixedly hold a collimator lens and a ferrule. The ferrule holds the fiber terminal section tilted relative to an optical axis of the collimator lens.

Abstract: An apparatus for generating a short-pulse laser using a temporally modulated sideband gain is provided. The apparatus includes a laser diode and an external reflector. By use of a time difference resulted by a nanosecond laser pulse signal at the external reflector, a sideband gain is obtained for generating a short-pulse picosecond laser output.

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 short light pulse generation device includes: a light pulse generation portion that has a quantum well structure and generates a light pulse; a frequency chirping portion that has a quantum well structure and chirps a frequency of the light pulse; a light branching portion that branches a chirped light pulse; and a group velocity dispersion portion that has a plurality of optical waveguides, on which each of a plurality of the light pulses branched in the light branching portion is incident, and produces a group velocity difference depending on a wavelength with respect to a plurality of branched light pulses, wherein light path lengths of the light pulses in a plurality of light paths before the light pulse is branched in the light branching portion and then incident on the plurality of optical waveguides of the group velocity dispersion portion are equal to each other.

Abstract: A master oscillator power amplifier (MOPA) system includes an oscillator having a neodymium-doped gadolinium vanadate gain-medium and delivering seed-pulses. A length of single mode fiber is used to broaden the spectrum of the seed pulse. An amplifier having a neodymium-doped yttrium vanadate gain-medium amplifies the spectrally broadened seed-pulses. The gain-spectrum of the amplifier partially overlaps the broadened pulse-spectrum, providing spectral selection of the seed-pulses in addition to amplification. This provides amplified output-pulses having a duration about one-third that of the corresponding seed-pulses.

Abstract: Provided is an apparatus for generating a single-polarization mode-locked laser capable of energy control. The apparatus for generating a single-polarization mode-locked laser is configured to adjust at least one of a focal length of a lens focusing laser light on a semiconductor saturable absorber mirror (SESAM) functioning as a saturable absorber, power of pump laser light, and reflectivity of an output coupler (OC) to set fluence, which is defined as energy density per unit area of the laser light incident on the saturable absorber, to be greater than reference fluence, which is energy density per unit area of the laser light incident on the saturable absorber when reflectivity of the saturable absorber is a maximum. Accordingly, it is possible to generate a single-polarization mode-locked laser, of which energy can be controlled, without generating multiple pulses.

Abstract: This disclosure demonstrates successfully using single, polycrystalline, hot pressed ceramic, and thin film Fe doped binary chalcogenides (such as ZnSe and ZnS) as saturable absorbing passive Q-switches. The method of producing polycrystalline ZnSe(S) yields fairly uniform distribution of dopant, large coefficients of absorption (5-50 cm?1) and low passive losses while being highly cost effective and easy to reproduce. Using these Fe2+:ZnSe crystals, stable Q-switched output was achieved with a low threshold and the best cavity configuration yielded 13 mJ/pulse single mode Q-switched output and 85 mJ in a multipulse regime.

Abstract: A laser device of a so-called laser ignition is provided, in which the heat dissipation is improved between a combustion chamber window and a housing, and the cooling or temperature of the combustion chamber window is able to be adjusted within broad limits by simple modifications.

Abstract: The bandwidth selection mechanism includes a first actuator mounted on a second face of a dispersive optical element, the second face being opposite from a reflective face, the first actuator having a first end coupled to a first end block and a second end coupled to a second end block, the first actuator being operative to apply equal and opposite forces to the first end block and the second end block to bend the body of the dispersive optical element along the longitudinal axis of the body and in a first direction normal to the reflective face of the dispersive optical element. The bandwidth selection mechanism also includes a second actuator being operative to apply equal and opposite forces to bend the body along the longitudinal axis of the body, in a second direction perpendicular to the reflective face of the dispersive optical element.