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 he completely shut down to lower the level of the measured inversion.

Abstract: Dry oxygen, dry air, or other gases such as ozone are hermetically sealed within the package of the external cavity laser or ASE swept source to avoid packaging-induced failure or PIF. PIF due to hydrocarbon breakdown at optical interfaces with high power densities is believed to occur at the SLED and/or SOA facets as well as the tunable Fabry-Perot reflector/filter elements and/or output fiber. Because the laser is an external cavity tunable laser and the configuration of the ASE swept sources, the power output can be low while the internal power at surfaces can be high leading to PIF at output powers much lower than the 50 mW.

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: The present invention relates to a higher-order dispersion compensation device (210), the device being adapted to cooperate with a pair of optical components (P1, P2), e.g. a pair of prisms, being arranged to compensate first-order dispersion by separating different wavelengths spatially. The compensation device (210) has the form of a phase plate, wherein the phase change for each wavelength is adjusted by designing the height (h) at the corresponding position (x) of the plate so as to substantially compensate for higher-order dispersion. The invention is advantageous for obtaining a higher-order dispersion compensation device which is relatively simple to construct and use making it a quite cost-effective device. The invention also relates to a corresponding optical system and method for compensating dispersion where this is important, e.g. in a multiple-photon imaging system.

Abstract: The closed cycle solid state optically pumped gas hybrid (chemical recovery) system utilizes a laser diode excited solid state, fiber or bulk, laser as a pump for a molecular gas, or gas mix, medium. The existence of efficient high power laser diode excited solid state fiber or bulk lasers, output spectrally matched to suitable principle and excited level 1st and 2nd overtones of relevant gases, is the enabling system technology. The utilization of such in combination with suitable gases introduces a range of viable, in principle sourcing on laser diodes and thus effectively laser diode pumped, gas laser systems with access to the approximately 3.5 ?m to approximately 5.2 ?m and approximately 9 ?m to approximately 11 ?m spectral regions. Continuous wave or pulsed operation, with significant energy capability courtesy of solid state storage, is admitted.

Abstract: An optical system having coherence reduction capabilities includes a light source for generating a first light pulse; an asymmetrical pulse stretcher arranged to receive the first light pulse and to generate multiple light pulses, during a pulse sequence generation period, wherein the asymmetrical pulse stretcher includes multiple optical components which define a loop and a condenser lens is located between the asymmetrical pulse stretcher and an object, for directing the multiple pulses toward an area on the object At least two optical components of the multiple optical components are positioned in an almost symmetrical manner in relation to each other and introduce a coherence-related difference between at least two pulses of the multiple pulses. The pulse sequence generation period does not exceed a response period of a detector.

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: A master oscillator may include: a pumping laser that outputs pumping light; a seed laser that is oscillated by the pumping light; an amplifier that amplifies the pulsed laser light outputted by the seed laser using the pumping light; at least one optical shutter disposed in the optical path between the seed laser and the amplifier; and a controller that causes the pumping laser to oscillate continuously at a predetermined repetition rate and that controls the optical shutter to open and close.

Abstract: A laser system is provided which selectively excites Raman active vibrations in molecules. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and remote sensing.

Abstract: An apparatus for producing coherent pulsed light with a fiber-based master oscillator/fiber amplifier architecture includes a fiber-coupled mode-locked laser source. The fiber-coupled mode-locked laser source is configured to provide pulses having a pulse duration of less than 1 ns. The apparatus also includes a fiber-coupled amplitude modulator optically coupled to the fiber-coupled mode-locked laser source. The fiber-coupled amplitude modulator is capable of gate durations greater than 1 ns. The apparatus further includes a saturated fiber power amplifier optically coupled to the fiber-coupled amplitude modulator.

Abstract: A system for emitting a polychromatic light, has a laser cavity device used to optically pump the laser cavity emit radiation according to at least one excitation wavelength and light guiding mechanism arranged in such a way as to supply a polychromatic light to an outlet in the event of excitation by the radiation in a non-linear interaction regime. In the system, the guiding mechanism is arranged inside a cavity formed by at least two sub-cavities, a first sub-cavity forming the laser cavity and a second sub-cavity comprising the guiding mechanism, the first and second sub-cavities being coupled.

Abstract: A laser system capable of phase and/or amplitude manipulation of the output pulses is provided. In another aspect, a laser system includes a self-referenced pulse characterization method. A further aspect uses spectral amplitude modulation to isolate spectral bands by scanning one or more transmission slits or openings, and measuring and/or calculating the first derivative of a phase (group delay) across an entire spectrum. A single-beam pulse shaper-based technique for spectrometer-free measurement and compensation of laser pulse phase distortions is also provided in an additional aspect.

Abstract: A deep ultraviolet light source includes a master oscillator producing a seed light beam; a regenerative ring amplifier receiving the seed light beam from the master oscillator and outputting an output light beam, the regenerative ring amplifier including a set of optical components that define a plane of a closed ring; and a divergence control device within the master oscillator or between the master oscillator and the regenerative ring amplifier and configured to reduce a divergence of the output light beam along a normal direction, the normal direction being perpendicular to the plane of the ring.

Abstract: A wavelength-tunable light source apparatus includes a first light source apparatus and a second light source apparatus. The first light source apparatus is capable of changing an oscillation wavelength and includes a resonator. The resonator includes an optical amplification medium for amplifying light and a waveguide having wavelength distribution. The second light source apparatus is connected to the waveguide and configured to introduce pulsed light as modulation light to the first light source apparatus. The oscillation wavelength is controlled by active mode locking employing cross-gain modulation using the modulation light. The pulse width of the modulation light has a duration shorter than a duration of a half period of a driving signal for generating the modulation light.

Abstract: A low white frequency noise tunable semiconductor laser source is presented. The laser source includes a single-mode semiconductor laser assembly which generates a laser beam having a tunable frequency over a spectral range of interest. An optical filter is provided in the path of the laser beam. The optical filter has multiple spectral features distributed over the entire spectral range of interest. Each spectral feature has a narrow spectral range. A locking mechanism is further provided and is controllable for locking a spectral alignment between the frequency of the laser beam and any selected one of the spectral features of the optical filter.

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 synchronously pumped optical parametric oscillator (OPO) comprises a nonlinear optical medium positioned in an optical resonator (e.g., a ring resonator) and is pumped by a pump laser source. A first arrangement includes a positioning mechanism for translating the nonlinear optical medium so OPO resonant modes propagate through one of multiple longitudinal regions arranged for differing odd orders of quasi-phase-matching. A second arrangement includes a pump fiber laser oscillator stretched to adjust its repetition rate to match that of the OPO. A third arrangement includes a time-domain-multiplexer (TDM) fiber loop between a pump fiber laser oscillator and fiber laser amplification stage(s). The TDM loop increases the pump repetition rate to enable increased average pump power without increased peak power.

Abstract: Systems and methods provide laser pulse equalization at different pulse repetition frequencies (PRFs). After initially pumping a lasing medium from a first pumping level to a peak pumping level, a controller may cause a pump source to continue pumping the lasing medium according to a pulse equalization pumping curve. The equalization pumping curve may be determined based on testing laser pulse parameters at different PRFs to achieve an optimal equalization result of the pulse parameters. The optimization metric used to evaluate various equalization pumping curves may include a consistency of the pulse energy level, peak power level, and/or pulse width of the laser under different PRFs. The equalization pumping curve may be a descending curve from the peak pumping level to the first pumping level. The equalization pumping curve may be a linearly declining curve, a substantially exponentially declining curve, a parametrically declining curve, or any other curve type.

Abstract: A system for homogenizing a laser pulse emitted by a laser source in order to illuminate a target homogeneously, the system having, between the laser source and the target: a phase plate constituted by a plurality of subpupils capable of generating a plurality of delayed laser beams towards the target, the path difference ?d between two adjacent delayed laser beams being greater than or equal to the length of the temporal coherence Tc of the laser pulse, and focusing device; wherein the subpupils and the focusing device are adjusted so that the delayed laser beams are superimposed on the target in a homogeneous spot.

Abstract: Pulsed light source comprising pulse generation means (1), such as an optical oscillator, whose output is divided into three arms: two arms (3, 4) to generate a CEP-stable, ultrabroadband idler output; and a third arm (5) to generate a narrowband pump output. The pump output and idler output seed an OPCPA (13), generating stable ultrashort pulses.

Abstract: The pulse light source comprises a seed light source, a first YbDF, a band-pass filter, a second YbDF, and a third YbDF, and has the MOPA structure. The band-pass filter inputs pulse light which is outputted from the seed light source and amplified by the first stage YbDF, and outputs, while separating a wavelength band of the inputted pulse light into a shorter wavelength side and a longer wavelength side with reference to a peak wavelength of the inputted pulse light, the attenuated pulse light after attenuating the optical power on one side more than the optical power on the other side between the shorter and longer wavelength sides.

Abstract: A laser marker/designator has an energy storage and conversion circuit providing a constant input current to a solid state pulsed pump diode.

Abstract: Apparatus and method for generating controlled-linewidth laser-seed-signals for high-powered fiber-laser amplifier systems. In some embodiments, the natural chirp (frequency change of laser light over a short start-up time) of a DBR laser diode when driven by pulsed current is used to broaden the linewidth of the laser output, while adjusting the peak current and/or the pulse duration to obtain the desired linewidth.

Abstract: System for converting relatively long pulses from rep-rate variable ultrafast optical sources to shorter, high-energy pulses suitable for sources in high-energy ultrafast lasers. Fibers with positive group velocity dispersion (GVD) and self phase modulation are advantageously employed with the optical sources. These systems take advantage of the need for higher pulse energies at lower repetition rates so that such sources can be cost effective.

Abstract: The invention relates to a laser amplification system for generating retrievable laser pulses having at least one laser source, in particular with a pulse selector arranged downstream thereof for the targeted selection of amplifiable laser pulses, a laser medium for amplifying laser pulses generated by the laser source and a loss modulator, wherein the loss modulator is arranged and connected such that said modulator modulates the amplification of the laser pulses by the laser medium by loss generation so that the retrievable laser pulses are provided with a predefined pulse time and/or pulse energy. Before an amplification process for one of the laser pulses, the current amplification of the laser medium is determined and the loss generation is controlled by the loss modulator depending on the current amplification of the laser medium.

Abstract: Disclosed is a laser apparatus of amplifying a laser pulse output using an anisotropic laser crystal through chirped pulse amplification. The laser apparatus includes a laser resonator. The laser resonator includes a plurality of anisotropic laser crystals, generates a shorter femtosecond pulse by widening a spectrum bandwidth through a combination of different gain spectrum distributions using the anisotropic laser crystals, and allows a laser beam to travel in axial directions with different thermal characteristics of the anisotropic layer crystals in order to reduce a thermal effect.

Abstract: The various laser architectures described herein provide increased gain of optical energy as well as compensation of optical phase distortions in a thin disk gain medium. An optical amplifier presented herein provides for scalable high energy extraction and gains based on a number of passes of the signal beam through a gain medium. Multiple, spatially separate, optical paths may also be passed through the same gain region to provide gain clearing by splitting off a small percentage of an output pulse and sending it back through the amplifier along a slightly different path. By clearing out the residual gain, uniform signal amplitudes can be obtained.

Abstract: System for converting relatively long pulses from rep-rate variable ultrafast optical sources to shorter, high-energy pulses suitable for sources in high-energy ultrafast lasers. Fibers with positive group velocity dispersion (GVD) and self phase modulation are advantageously employed with the optical sources. These systems take advantage of the need for higher pulse energies at lower repetition rates so that such sources can be cost effective.

Abstract: Dual laser-power-level control and calibration system for burst-mode and continuous-mode transmitter. A first signal path receives a transmit signal that also drives the transmit laser, and a second signal path receives the output of a monitor diode. The first and second signal paths include filtering so that the two signal paths have a similar frequency response. The upper and lower excursions in both signal paths are compared, and the power levels of the optical transmitter are adjusted based on those comparisons. Embodiments with one control loop and two control loops are disclosed.

Abstract: Provided are an apparatus and method for stabilizing a pulse of a fiber-type femtosecond laser, and more particularly, to an apparatus for stabilizing a pulse of a fiber-type femtosecond laser, which adjusts a distance between a saturable absorption material and an optical fiber connection unit of the femtosecond laser to automatically perform mode-locking, thereby obtaining a laser pulse stabilized for a long time, and a method for stabilizing the pulse of the fiber-type femtosecond laser. The apparatus for stabilizing a pulse of a fiber-type femtosecond laser in a fiber-type femtosecond laser system including a pump laser (100) and a fiber cavity (200) includes a distance adjustment part (300) adjusting a distance (d) between a saturable absorption material (700) and a connection unit of an optical fiber (310) which are provided within the fiber cavity (200).

Abstract: A laser system can include a laser and a laser output modulator to modulate the output of the laser.

Abstract: Emissive quantum photonic imagers comprised of a spatial array of digitally addressable multicolor pixels. Each pixel is a vertical stack of multiple semiconductor laser diodes, each of which can generate laser light of a different color. Within each multicolor pixel, the light generated from the stack of diodes is emitted perpendicular to the plane of the imager device via a plurality of vertical waveguides that are coupled to the optical confinement regions of each of the multiple laser diodes comprising the imager device. Each of the laser diodes comprising a single pixel is individually addressable, enabling each pixel to simultaneously emit any combination of the colors associated with the laser diodes at any required on/off duty cycle for each color. Each individual multicolor pixel can simultaneously emit the required colors and brightness values by controlling the on/off duty cycles of their respective laser diodes.

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: In order to maintain a constant laser output pulse power in a RF-energized, sealed-off, diffusion cooled, pulsed, CO2 gas-discharge laser, each laser output pulse is generated by train or burst of shorter RF pulses. When the time between laser output pulses becomes short enough that the power in one pulse would be reduced by gas-discharge heating effects of a previous pulse, power in the RF pulse trains is varied by varying the duration or duty cycle of pulses in the bursts, thereby keeping output-pulse power in the laser output pulses constant. RF pulses in any burst can have a different duration for tailoring the temporal shape of a corresponding laser-output pulse.

Abstract: The present invention relates to an apparatus for producing optical pulses of a desired wavelength. The apparatus includes an optical pulse source operable to generate input optical pulses at a first wavelength. The apparatus further includes a higher-order-mode (HOM) fiber module operable to receive the input optical pulses at the first wavelength, and thereafter to produce output optical pulses at the desired wavelength by soliton self-frequency shift (SSFS). The present invention also relates to a method of producing optical pulses having a desired wavelength. This method includes generating input optical pulses using an optical pulse source, where the input optical pulses have a first wavelength and a first spatial mode.

Abstract: A tunable laser system having fine and coarse wavelength discrimination is provided. The tunable laser system includes a first filter having a first free spectral range (FSR) and a second filter having a second FSR different from the first FSR. The first filter provides a first series of pulses from a first portion of a laser output, and a second filter provides a second series of pulses from a second portion of the laser output. A processing system compares the first series of pulses and the second series of pulses to identify a series of markers, in which the markers are separated by a beat period of the first series of pulses and the second series of pulses. Advantageously, the series of markers may be used for mode-hop detection and/or for wavelength referencing.

Abstract: Methods and systems for generating pulses of laser radiation at higher repetition rates than those of available excimer lasers are disclosed that use multiple electronic triggers for multiple laser units and arrange the timings of the different triggers with successive delays, each delay being a fraction of the interval between two successive pulses of a single laser unit. Methods and systems for exposing nanoscale patterns using such high-repetition-rate lasers are disclosed.

Abstract: Techniques and devices for producing short laser pulses based on chirping and stretching of short seed laser pulses and subsequent power amplification. Such laser pulses with relatively narrow spectral bandwidths can be used in certain laser applications where narrow spectral bandwidth laser pulses are advantageous. In the examples described in this document, the generated laser pulses with relatively narrow spectral bandwidths may have relatively long pulse durations (e.g., greater than 1 ps) due to the stretching operation in the pulse generation.

Abstract: Processing workpieces such as semiconductor wafers or other materials with a laser includes selecting a target to process that corresponds to a target class associated with a predefined temporal pulse profile. The temporal pulse profile includes a first portion that defines a first time duration, and a second portion that defines a second time duration. A method includes generating a laser pulse based on laser system input parameters configured to shape the laser pulse according to the temporal pulse profile, detecting the generated laser pulse, comparing the generated laser pulse to the temporal pulse profile, and adjusting the laser system input parameters based on the comparison.

Abstract: A frequency-drift amplification device for a pulsed laser, including: a stretcher for time-stretching an incident laser pulse; at least one amplifying medium for amplifying the laser pulse; a main compressor for time-compressing the laser pulse to a desired duration for an output pulse of the amplification device; and at least one adjustment compressor between the stretcher and the main compressor, and in which the laser pulse undergoes four diffractions on diffraction gratings to time-compress the stretched laser pulse to a duration that is greater than the desired duration for the output pulse of the amplification device.

Abstract: A laser scanning device and a method using the same are provided. The laser scanning device includes a laser output unit, a shape rotation unit, a scanning unit and a control unit. The laser output unit is used to output a laser beam. The shape rotation unit is disposed on a propagation path of the laser beam for rotating a spot of the laser beam by a predetermined angle. The scanning unit receives the laser beam whose spot has been rotated by the predetermined angle to scan a work piece set on a carrier unit. The control unit is set between the shape rotation unit and the scanning unit for generating the predetermined angle based on a scanning position of the scanning unit.

Abstract: The invention relates to a method for coupling a first and second laser (1, 2) having an adjustable difference of their pulse frequencies, which is not equal to zero, wherein the method comprises the following steps: derivation of a first harmonic signal and a signal of the Mth harmonic from the time progression of the light intensity of the pulses emitted by the first laser, mixing of the first harmonic signal and the signal of the Mth harmonic, in order to obtain a first mixed signal, derivation of a second harmonic signal and a signal of the Nth harmonic from the time progression of the light intensity of the pulses emitted by the second laser, mixing of the second harmonic signal and the signal of the Nth harmonic, in order to obtain a second mixed signal, wherein the first and second harmonic signal and the Mth and Nth harmonic are selected in such a manner that the frequencies of the first and second mixed signal are identical, wherein the method furthermore comprises regulation of the pulse frequen

Abstract: A laser system may include a master oscillator that outputs pulsed laser light, an amplification device that amplifies the pulsed laser light outputted from the master oscillator, and a controller that controls the master oscillator and the amplification device. The master oscillator may have a pumping laser that outputs pumping light, a seed laser that is oscillated by the pumping light, an amplifier that amplifies the pulsed laser light outputted by the seed laser using the pumping light, and at least one optical shutter disposed in the optical path between the seed laser and the amplifier. The controller may control the opening and closing of the optical shutter and discharging of the amplification device so that the amplification device discharges when the pulsed laser light that has passed through the optical shutter passes through the amplification device.

Abstract: An amplification device with frequency drift for a pulsed laser includes a stretcher temporally stretching an incident laser pulse, at least one amplifying medium for amplifying the stretched laser pulse, and a compressor for temporally compressing the stretched and amplified laser pulse. The compressor includes an amplifying medium for amplifying a partially temporally compressed laser pulse, increasing energy yield of the amplifier.

Abstract: Variable repetition rate and wavelength optical pulse source, comprising a fixed or variable repetition rate source of supercontinuum pulses; a wavelength tunable optical bandpass filter to filter the supercontinuum pulses at two or more wavelengths, wherein said source of supercontinuum pulses and said wavelength tunable optical bandpass filter are configured such that the optical pulse source can provide variable repetition rate and variable wavelength optical pulses including a series of repetition rates with selected wavelength-varying pulse trains.

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 method of generating ultrashort pulses with wavelengths greater than 2 ?m comprising a short pulse diode laser or fiber laser operating at a wavelength of 1 ?m or greater with a pulse width of 10 ps or greater, one or more amplification stages to increase the peak power of the pulsed source, a nonlinear fiber stage whereby the dispersion of the nonlinear fiber is anomalous at the pulsed source wavelength such that the fiber breaks up the pulse into a series of sub-ps pulse train through modulation instability which may be seeded by spontaneous noise which are then wavelength shifted in one or more stages by soliton self frequency shift in anomalous dispersion fiber or Raman in normal dispersion fiber and amplified in one or more stages to generate a high peak power ultrashort pulse (<1 ps) source at a wavelength of 2.4 ?m or greater.

Abstract: The invention relates to an optical assembly (1) comprising a pulsed light source (2) for generating primary light pulses (4), a pulse splitter (5) for splitting said primary light pulses (4) into first and second secondary light pulses (7), and a delay element (8) for delaying said second secondary light pulses (7) relative to said first secondary light pulses (6), where the pulse repetition rate of said pulsed light source (2) is variable in order to change a temporal delay between different secondary light pulses (6,7) The invention is characterized in that said optical assembly (1) comprises a thermal insulation (12), a temperature stabilizer (16) or a temperature compensator (13) for said delay element (8) and/or a control circuit (27) for determining and controlling a drift of said pulse repetition rate.

Abstract: Apparatus, systems, and methods having a frequency comb of large spacing can be used in a variety of applications. In various embodiments, a frequency comb is generated from a slave laser by injecting an optical output from a drive laser into the slave laser. One or more parameters of the drive laser and/or the slave laser can be adjusted such that a frequency comb can be generated at a multiple of the repetition rate of the drive laser. Additional apparatus, systems, and methods are disclosed.

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.