Abstract: A multi-wavelength mid-infrared laser pulse train cavity dumped laser based on Nd:MgO:APLN crystal is disclosed. In response to the needs in the field of differential absorption lidar, it is necessary to introduce multi-fundamental frequency light pulse accumulation and superposition, and parametric light synchronization pulse compression technology in the multi-wavelength mid-infrared laser operating mechanism. To this end, a splayed parametric light oscillation cavity formed in conjunction with a Nd:MgO:APLN crystal is disclosed, wherein it is possible to obtain multi-wavelength mid-infrared laser pulse train output with narrow pulse width and high peak power, meeting the needs of differential absorption lidar for mid-infrared lasers.

Abstract: Automatically optimizing a predictive dynamic bending light function of a vehicle lighting system comprises configuring a bending light control unit for controlling the lighting system with initial bending light control parameter values as control parameter values to be used, configuring a classification unit for automatically classifying a performance of the bending light control unit into a desired and at least one further performance class, depending on output values of the control unit, configuring a control parameter optimization unit for ascertaining updated control parameter values depending on input values of the control unit and classifications of the performance assigned to them, as well as acquiring driving trajectory parameter values as the input values during a journey, ascertaining output values of the control unit, automatically classifying the performance depending on the ascertained output values, ascertaining updated control parameter values and adapting the control parameter values to be us

Abstract: A driving and stabilization system for a pump laser, and a pump laser system. The driving and stabilization system includes a constant current stabilization device, a constant temperature stabilization device, a power detection device, an environment detection device, and a control device. The constant current stabilization device includes a voltage comparison circuit, a constant current driving circuit, and a switch protection circuit. The constant temperature stabilization device includes an internal constant temperature stabilization circuit and an external constant temperature stabilization circuit.

Abstract: The present disclosure relates to laser systems and laser pulse measurement methods.

Abstract: A system is described. The system includes HNLF for generating an optical frequency comb and a single mode fiber for reducing a pulse duration of comb. The system includes a FRM to reflect the light in back propagation through the HNLF and the single mode fiber. Perturbations in a state of polarization caused by the HNLF and the single mode fiber are cancelled between the forward propagation and the backward propagation. The optical frequency comb may then be polarization maintaining without an active component such as a polarization controller and a feedback circuit.

Abstract: A method of practicing the invention includes at least the following steps of generating pump laser radiation having a spectrum containing a plurality of equidistant spectral lines; passing the pump laser radiation through a non-linear medium of a singly resonant, single-frequency optical parametric oscillator, wherein the pump laser radiation is continuously a wave or is pulsed, wherein the pulse duration in the latter case is longer than the time the optical parametric oscillation requires to reach its steady state; and coupling out the non-resonant idler or signal laser radiation from the optical parametric oscillator as usable frequency converted laser radiation. Further provided is a laser device used to carry out the method of the invention.

Abstract: A laser system according to one aspect of the present disclosure includes a first solid-state laser device, a wavelength conversion system, an excimer amplifier, and a control unit. The first solid-state laser device includes a first multiple semiconductor laser system, a first semiconductor optical amplifier, and a first fiber amplifier. The first multiple semiconductor laser system includes a plurality of first semiconductor lasers configured to perform continuous wave oscillation in a single longitudinal mode with different wavelengths, a first spectrum monitor, and a first beam combiner. The control unit controls an oscillation wavelength and light intensity of each line of a first multiline spectrum generated by the first semiconductor lasers to obtain an excimer laser beam having at least a target center wavelength or a target spectral line width instructed by an external device.

Abstract: An all-fiber supercontinuum (SC) optical source utilizes a combination of a seed pulse supply of short-duration optical pulses with a highly non-linear optical medium in the form of two or more concatenated sections of highly non-linear optical fiber (HNLF) of different dispersion values and lengths. The two or more sections of HNLF are configured to include at least one section that exhibits a positive dispersion value and one section that exhibits a negative dispersion value. Non-linear effects such as self-phase modulation (SPM), cross-phase modulation (XPM), Raman amplification, and the like, cause the seed pulses to broaden as they propagate through each section of HNLF, where the differences between the dispersion values, as well as the lengths of each fiber section, are particularly configured to create an SC output that is wide and smooth, exhibiting a stable intensity and high coherence level.

Abstract: A supercontinuum radiation source including a modulator being operable to modulate pump laser radiation including a train of radiation pulses to provide modulated pump laser radiation, the modulation being such to selectively provide a burst of the pulses; and a hollow-core photonic crystal fiber being operable to receive the modulated pump laser radiation and excite a working medium contained within the hollow-core photonic crystal fiber so as to generate supercontinuum radiation.

Abstract: A passively, Q-switched laser operating at an eye safe wavelength of between 1.2 and 1.4 microns is described. The laser may operate at a lasing wavelength of 1.34 microns and use a gain element of Nd:YVO4 and a saturable absorber element of V:YAG. The position of the resonator axial mode spectrum relative to a gain peak of the gain element is controlled to yield desired characteristics in the laser output.

Abstract: There is provided a laser apparatus for a printed electronic system according to an exemplary embodiment of the present invention including: a laser generating unit which oscillates a laser beam; a laser changing unit which changes an intensity or a wavelength of the laser beam oscillated from the laser generating unit; a laser control unit which controls the intensity or a magnitude of the wavelength of the laser beam which is changed by the laser changing unit; and a laser steering unit which changes a traveling direction of the laser beam output from the laser changing unit to be directed to a target, and the laser control unit controls the intensity or the magnitude of the wavelength of the laser beam in accordance with a state of a printing pattern formed on the target.

Abstract: A pulsed light generation device includes: an optical coupler having four input/output ports including a first port, a second port, a third port and a fourth port; a connection optical path that connects the third port with the fourth port; and a phase modulation element disposed in the connection optical path. The optical coupler branches pulsed light input to the first port and outputs the branched input pulsed light as first-direction pulsed light and second-direction pulsed light to the third port and to the fourth port. The modulation element applies phase modulation to either one of the first-direction pulsed light and the second-direction pulsed light, thereby outputs output pulsed lights through the first port and the second port, wherein a waveform of one of the pulsed lights output through the first port is different from a waveform of the other of the output pulsed lights output through the second port.

Abstract: A device for generating laser radiation comprises a temperature-controlled optical setup comprising an optically non-linear solid state medium arranged in a resonator and an active region. The outgoing laser radiation is generated from a pump beam introduced into the optically non-linear solid state medium. A first temperature actuator and a second temperature actuator configured to independently adjust temperature values in the active region of the optically non-linear solid state medium. The first temperature actuator is configured regulate a length of the resonator by setting a first temperature value within a first portion of the active region. The second temperature actuator is configured to match phases of wavelengths generated by the outgoing laser radiation and phases of wavelengths of the pump beam radiation by setting a second temperature value within a second portion of the active region.

Abstract: An all-optical optical parametric oscillator includes a laser module, a temperature control module, a plurality of filters and a beam splitter arranged in sequence. A bulk material or waveguide material is arranged in the temperature control module. Both ends of the bulk material are provided with a first OPO cavity mirror M1? and a second OPO cavity mirror M2?. Each of the first OPO cavity mirror M1? and the second OPO cavity mirror M2? is coated with a high-reflectivity film with respect to an OPO signal light and an OPO idler light, and coated with a high-transmittance film with respect to an OPO pump light, a poling fundamental frequency light and a poling frequency doubled light. The temperature of the material is changed by changing the temperature of the temperature control module to realize temperature tuning of wavelength ?s of the OPO signal light and wavelength ?i of the OPO idler light.

Abstract: An apparatus includes a non-linear optical crystal configured to perform harmonic wavelength conversion. The apparatus also includes first and second heaters contacting opposite sides of the optical crystal, where the first and second heaters are configured to heat the optical crystal. The apparatus further includes first and second backing plates configured to hold the first and second heaters in contact with the optical crystal. The apparatus also includes an internal mount defining a space configured to receive at least a portion of the optical crystal. In addition, the apparatus includes an external cover around at least a portion of the internal mount.

Abstract: To prevent an output decrease of laser light due to impurities formed in a Q switch. A laser machining device includes a Q-switch housing section configured by housing a Q switch and a first mirror and a wavelength converting section including a housing in which a transmission window section capable of transmitting a fundamental wave is formed, the wavelength converting section being configured by airtightly housing, with an internal space surrounded by the housing, at least a first wavelength conversion element, a second wavelength conversion element, and a second mirror. A resonator forming a resonant optical path passing through the transmission window section is configured by the first mirror in the Q-switch housing section and the second mirror in the wavelength converting section.

Abstract: The effective coherence length of a single-frequency, solid-state laser is limited to reduce spurious, secondary holograms in conjunction with a holographic recording. The wavelength of the laser is varied or ‘scanned’ with high precision over a very small wavelength range. In an embodiment, the temperature of the laser's resonant cavity optical bench is altered, causing the dimension of the cavity to change and the emission wavelength to move in a controlled manner. The changing wavelength is monitored at high resolution, and a feedback control loop updates the temperature set-point to keep the monitored laser wavelength moving at a desired rate of change through a desired range. As the wavelength of the laser is scanned, the phase of the holographic interference pattern is locked at a position of maximum coherence/contrast within the holographic film aperture.

Abstract: Techniques for eye-tracking in a near-eye display system are disclosed. One example of a near-eye display system includes a substrate transparent to visible light and configured to be placed in front of a user's eye, one or more light sources configured to emit illumination light invisible to the user's eye, one or more input couplers configured to couple the illumination light into the substrate, and one or more grating couplers each configured to couple a portion of the illumination light out of the substrate and towards the user's eye at a different direction. The illumination light coupled into the substrate propagates within the substrate through total internal reflection. The one or more grating couplers include at least one of a chirped surface-relief grating coupler or a volume Bragg grating coupler.

Abstract: In a device for generating output laser pulses having a tunable central wavelength, based on parametric amplification, a laser system is to be provided that has less complexity, but that nevertheless provides great tunability for the wavelength, permits rapid switching of the wavelength, and allows the spectral bandwidth of the emitted pulses to be adjusted. This is attained in that for adjustability of the bandwidth of the output laser pulses, an optical device is provided that is designed to influence the spectral phase of the pump pulses as a function of the spectral phase of the seed pulses.

Abstract: Methods and systems for Raman spectroscopy and context imaging are disclosed. One or two lasers can be used to excite Raman scattering in a sample, while a plurality of LEDs can illuminate the sample at a different wavelength. The LED light is collected by a lenslet array in order to enable a high depth of field. Focusing of the image can be carried out at specific points of the image by processing the light collected by the lenslet array.

Abstract: According to the present disclosure, an illumination apparatus includes a pump radiation source for emitting pump radiation, a phosphor element for converting the pump radiation into conversion light and a carrier, on which the phosphor element is mounted, which carrier is made of a carrier material which is transparent at least for the pump radiation and has a refractive index ncarrier. The pump radiation passes through the carrier, exits at an exit surface of the carrier and is then incident on a pump radiation input coupling surface of the phosphor element that is arranged at the exit surface. The pump radiation in the carrier is incident on the exit surface of the carrier with a centroid direction, which centroid direction is inclined with respect to a surface normal on the exit surface by an exit angle ?out?0°, and ?out<?c with ?c=arcsin(1/ncarrier).

Abstract: A THz laser source includes a first generator suitable for emitting at least one first light emission and one second light emission of frequencies that are multiples of a first reference frequency; a second generator suitable for emitting at least one first light emission and one second light emission of frequencies that are multiples of a second reference frequency different from the first reference frequency; the THz laser source furthermore comprises a nonlinear crystal suitable for forming, from the first light emissions emitted by each of the first and second generators, a THz light emission generated by difference-frequency generation, of frequency comprised between 0.3 THz and 10 THz; and at least one first frequency-stabilizing module allowing the frequency of one of the second emissions emitted by one of the first and second generators to be stabilized to an atomic transition.

Abstract: A resonator is provided that includes opposing mirrors arranged substantially parallel to each other and separated to confine reflections for gain. A gain medium is between the opposing mirrors. A pump pumps the gain medium. At least one microrefractive element, or tens, hundreds, thousands, millions or more, stabilizes the resonator. The refractive element is disposed between the opposing mirrors and is configured to support a laser beam at a position of the refractive element. A method for producing laser light directs pump light onto one or a plurality of microrefractive elements. Reflections from the one or a plurality of microrefractive elements are confined in a resonator volume. Gain is provided in the resonator volume. Laser energy is emitted from the resonator volume.

Abstract: An arrangement includes a conversion element, an optoelectronic semiconductor component and a first carrier including a carrier plane, wherein the conversion element is arranged on the carrier plane, the optoelectronic semiconductor component emits a first electromagnetic radiation including a first beam direction and a first wavelength from a first spectral range during operation, the first electromagnetic radiation is directed onto the conversion element, the conversion element at least partly converts the first electromagnetic radiation into a second electromagnetic radiation including a second wavelength from a second spectral range, the first beam direction of the optoelectronic semiconductor component is oriented at an inclination with respect to the carrier plane, a housing including a housing cap is provided, the housing cap is configured in a hollow-body-like fashion, the housing cap and the carrier define an interior, the conversion element and the semi-conductor component are arranged in the interi

Abstract: A free-space optical communication link is proposed that utilizes phase-sensitive amplification of the received optical signal at the input to the receiver portion of the link. The transmitter component of the FSO link generates an idler signal that is transmitted through free space with the original data signal and used at the PSA in conjunction with a pump wave to impart gain onto the received information signal. The PSA performs four-wave mixing (FWM) of the data, idler and pump to create the amplified data signal. In one embodiment, the pump wave used to generate the idler at the transmitter is sent through free space with the information and idler signals and used by the PSA to perform amplification. Alternatively, the PSA may use a co-located pump laser, in combination with the received idler signal, to perform the phase-sensitive amplification process.

Abstract: Laser pulses from pulsed fiber lasers are directed to an amorphous silicon layer to produce a polysilicon layer comprising a disordered arrangement of crystalline regions by repeated melting and recrystallization. Laser pulse durations of about 0.5 to 5 ns at wavelength range between about 500 nm and 1000 nm, at repetition rates of 10 kHz to 10 MHz can be used. Line beam intensity uniformity can be improved by spectrally broadening the laser pulses by Raman scattering in a multimode fiber or by applying varying phase delays to different portions of a beam formed with the laser pulses to reduce beam coherence.

Abstract: Provided herein are a method and apparatus for controlling the wavelength of an external-cavity wavelength-tunable laser. The reflectivity or transmittance characteristics of a wavelength depend on the phase difference between light reflected by a wavelength-tunable filter and parasitic reflective light. Thus, when the temperature of a module and current applied to a phase control electrode and an external reflector are changed, the characteristics are changed in a periodic manner. The present disclosure relates to a wavelength control algorithm of determining combinations of these parameters to set conditions having optimum chirping characteristics at a desired wavelength.

Abstract: The amount of current provided to a laser diode of an optical network transceiver device, the power output of the optical network transceiver device, and the device temperature of the optical network transceiver device is monitored. Based at least in part on a detected fluctuation in at least one of the amount of current provided to the laser diode, the power output of the optical network transceiver device, and the device temperature of the optical network transceiver device, a determined expected life of the optical network transceiver device is dynamically adjusted.

Abstract: In the examples provided herein, an optical logic gate includes multiple couplers, where no more than two types of couplers are used in the optical logic gate, and further wherein the two types of couplers consist of: a 3-dB coupler and a weak coupler with a given transmission-to-reflection ratio. The optical logic gate also includes a first resonator, wherein the first resonator comprises a photonic crystal resonator or a nonlinear ring resonator, wherein in operation, the first resonator has a dedicated continuous wave input to bias a complex amplitude of a total field input to the first resonator such that the total field input is either above or below a nonlinear switching threshold of the first resonator, where the optical logic gate is an integrated photonic circuit.

Abstract: To provide a laser ignition device in which the ignition efficiency is improved and the laser pulse energy necessary for ignition is minimized by optimizing the pulse time width of laser. The laser ignition device includes: a pulse laser oscillator 1 configured to output a beam having a wavelength ? [?m] and a beam quality M2; an energy controller 2 configured to control energy of pulse laser outputted from the pulse laser oscillator 1; a lens 3 having a focal length f [mm] and configured to focus the pulse laser outputted from the pulse laser oscillator 1; and a pulse time width controller 14 configured to control a time width of the pulse laser, wherein the pulse time width controller 14 controls the time width of the pulse laser to be 0.6 to 2 ns.

Abstract: The present application relates to generating terahertz radiation, wherein a pump pulse is subjected to pulse front tilting, the thus obtained pump pulse having tilted pulse front is coupled into a nonlinear optical medium and THz pulse is generated by the optical medium in nonlinear optical processes, particularly by means of optical rectification by the pump pulse. The application also relates to a terahertz radiation source (100), comprising a pump source (10) for emitting a pump pulse and a nonlinear optical medium for generating THz pulse. The pump source (10) and the nonlinear optical medium define together a light path, said light path is arranged to guide the pump pulse from the pump source (10) to the nonlinear optical medium. A first optical element (20) having angular-dispersion-inducing property and imaging optics (30) are disposed in the light path after each other in the propagation direction of the pump pulse.

Abstract: An artificial saturable absorber uses additive pulse mode-locking to enable pulse operation of an on-chip laser operation. Four different artificial saturable absorbers are disclosed. The first includes an integrated coupler, two arms each containing some implementation of the end-reflector, and a phase bias element in one arm. The second includes an integrated directional coupler, two integrated waveguide arms, and another integrated coupler as an output. The third includes an integrated birefringent element, integrated birefringent-free waveguide, and integrated polarizer. And the fourth includes a multimode waveguide that allows for different modes to propagate in such a way that the difference in the spatial distribution of intensity causes a nonlinear phase difference between the modes.

Abstract: A laser system includes a seed source optically coupled to an extra cavity harmonic generator system may produce a round, non-astigmatic third harmonic output beam from a nominally round, non-astigmatic, diffraction limited input fundamental beam from the seed source. The system may include a second harmonic generation crystal. An input fundamental beam size is expanded in a non-walkoff direction for the SHG crystal at the SHG crystal input face. A higher harmonic generation crystal has an output face oriented at an oblique angle of incidence in a non-walkoff direction for the HHG crystal such that an output higher harmonic beam size is contracted in this direction. Expansion of the input fundamental beam at the SHG crystal input face exceeds reduction of third harmonic beam at the HHG crystal output face.

Abstract: The invention concerns a method for generating a laser beam (3) with different beam profile characteristics, whereby a laser beam (2) is coupled into one fiber end (1a) of a multi-clad fiber (1), in particular a double-clad fiber, and emitted from the other fiber end (1b) of the multi-clad fiber (1) and whereby, to generate different beam profile characteristics of the output laser beam (3), the input laser beam (2) is electively coupled either at least into the inner fiber core (4) of the multi-clad fiber (1) or at least into at least one outer ring core (6) of the multi-clad fiber (1), as well as a corresponding arrangement (10).

Abstract: Examples described herein generally relate to apparatus and methods for rapid thermal processing (RTP) of a substrate. The present disclosure discloses pulsed radiation sources, used to measure a broad range of low to high temperatures in the RTP chamber. In one example, two or more lasers, one of which emits pulses of radiation at 1,030 nm and one of which emits pulses of radiation at 1,080 nm, which measures temperatures below about 200° C., are used. In another example, two or more LEDs, one of which emits pulses of radiation at 1,030 nm and one of which emits pulses of radiation at 1,080 nm, are used. In yet another example, a broadband radiation source is used to emit pulses of radiation at least at 1,030 nm and 1,080 nm. These radiation sources are useful for detection of a broad range of low to high temperatures in the RTP chamber.

Abstract: An optical amplifying system is disclosed. The optical amplifying system includes a thermo-electric cooler (TEC), and a semiconductor laser diode (LD) mounted on the TEC. The semiconductor LD generating a modulated optical signal with a wavelength that depends on the temperature of the LD as controlled by the TEC. The optical amplifying system further includes a semiconductor optical amplifier (SOA) that amplifies the modulated optical signal. A feature of the optical amplifying system is that the temperature of the SOA is higher than that of LD.

Abstract: An optical parameter oscillator (OPO) is pumped at pump wavelength ?P to resonate at signal wavelength ?S. The OPO produces idler radiation at terahertz frequencies ?THz=c/?P?c/?S. The pump, signal, and idler radiation are substantially collinear.

Abstract: A device for the generation of supercontinuum in infrared fiber with a light source comprising a pulsed microchip laser operating at a wavelength greater than one micrometer, a nonlinear optical parametric element operated without a cavity, and an infrared fiber. Light from the laser is pumped into the nonlinear optical parametric element to generate two new wavelengths, and the output from the nonlinear optical parametric element is launched into the infrared fiber. Output from the infrared fiber has a bandwidth greater than the input laser bandwidth by at least 100% and an emission wavelength range from 2 to 14 micrometers.

Abstract: A method for extending and enhancing bright coherent high-order harmonic generation into the VUV-EUV-X-ray regions of the spectrum involves a way of accomplishing phase matching or effective phase matching of extreme upconversion of laser light at high conversion efficiency, approaching 10?3 in some spectral regions, and at significantly higher photon energies in a waveguide geometry, in a self-guiding geometry, a gas cell, or a loosely focusing geometry, containing nonlinear medium. The extension and enhancement of the coherent VUV, EUV, X-ray emission to high photon energies relies on using VUV-UV-VIS lasers of shorter wavelength. This leads to enhancement of macroscopic phase matching parameters due to stronger contribution of linear and nonlinear dispersion of both atoms and ions, combined with a strong microscopic single-atom yield.

Abstract: A system is provided for generating a laser beam via non-linear effects, including: a monofrequency continuous-wave laser source; and an external resonant cavity referred to as a microchip cavity. The microchip cavity is composite insofar as it is a unitary assembly of a plurality of materials g: at least one nonlinear crystal; an entrance mirror; a concave mirror deposited on a material fixed to the nonlinear crystal—the material on which the concave mirror is deposited is different from the constituent material of the nonlinear crystal; a first thermoelectric module for controlling the temperature of the nonlinear crystal; and at least one second thermoelectric module for controlling at least the temperature of the material on which the concave mirror is deposited.

Abstract: Provided herein are techniques for improved optical absorption measurements in the presence of time-varying etalons. In one aspect, a method for dynamic etalon fitting for adaptive background noise reduction in an optical sensor is provided. The method includes the steps of: obtaining a zero-gas spectrum measured using the optical sensor; obtaining an analyte gas spectrum of a target trace gas measured using the optical sensor; comparing the zero-gas spectrum and the analyte gas spectrum using fit parameters that compensate for drifting etalons in the optical sensor; and dynamically extracting the drifting etalons from the analyte gas spectrum to retrieve concentration of the target trace gas.

Abstract: A wavelength conversion element includes a crystal having a periodically poled structure in which polarization is inverted with an inversion period ? along a z-axis which is an input axis of a light pulse. The wavelength conversion element is configured to generate an output the inversion period ?(x) at each position x by change of the inversion period ? according to the position x, and when a target frequency linearly changing with the position x is set to fT(x)=b+ax, a frequency width of the output frequency is set to ?f(x), and the output frequency is set to f(x)=fT(x)+?(x), the output frequency is set to coincide with the target frequency within a range satisfying a condition |?(x)|??f(x).

Abstract: A hybrid resonator and amplifier combination for generating a high energy output signal. The combination comprises a beam splitter for splitting a pump laser beam into first and second portions. The second portion beam being conveyed to a resonator which operates in a single transverse mode to generating a signal wavelength beam. An output coupler of the resonator allows a first portion of the signal wavelength beam to pass therethrough while retaining a second portion of the signal wavelength beam within the resonator. A system dichroic mirror receives and directs both the first portion and the signal wavelength beam toward an amplifier. The amplifier receives both the first portion and the signal wavelength beam. The first portion, upon passing through the amplifier, creates gain which is used by the amplifier to amplify the signal wavelength beam generate the high energy output signal.

Abstract: Disclosed herein is a semiconductor laser element capable of suppressing a wavelength dependency of a reflection ratio. A reflective film of the semiconductor laser element includes an L1 layer arranged at a first position from the end faces of the resonator and having a refractive index of n1; and a periodic structure configured by layering a plurality of pairs of an L2N layer and an L2N+1 layer. The L2N layer has a refractive index of n2, and the L2N+1 layer has a refractive index of n3, where n2<n3. The L1 layer has a linear expansion coefficient of ±30% with respect to a linear expansion coefficient of the substrate and is made of a film having an optical film thickness thinner than ?/4. An L2 layer arranged at a second position from the end faces of the resonator is made of a film having an optical film thickness thinner than ?/4.

Abstract: An extra cavity harmonic generator system may produce a round, non-astigmatic third harmonic output beam from a nominally round, non-astigmatic, diffraction limited input fundamental beam. The system may include a second harmonic generation crystal. An input fundamental beam size is expanded in a non-walkoff direction for the SHG crystal at the SHG crystal input face. A higher harmonic generation crystal has an output face oriented at an oblique angle of incidence in a non-walkoff direction for the HHG crystal such that an output higher harmonic beam size is contracted in this direction. Expansion of the input fundamental beam at the SHG crystal input face exceeds reduction of third harmonic beam at the HHG crystal output face.

Abstract: According to one embodiment, a cavity with a cavity mode which is coupled to physical systems includes a spherical mirror and a plane mirror. The spherical mirror is provided at a birefringent crystal including the physical systems. The plane mirror is provided at the birefringent crystal opposite to the spherical mirror. The birefringent crystal has a first refractive index to light polarized in a first direction parallel to a polarization direction of the cavity mode on an optical axis of the cavity and a second refractive index to light polarized in a second direction parallel to the optical axis, the second refractive index being different from the first refractive index. A cavity length of the cavity and a mode waist radius of the cavity mode satisfy a specific condition.

Abstract: A semiconductor laser apparatus is provided. The semiconductor laser apparatus includes a mode-locked semiconductor laser device and an external resonator including a dispersion compensation system, wherein the semiconductor laser apparatus is configured to generate self modulation, to introduce a negative group velocity dispersion into the external resonator, and to provide spectral filtering after the external resonator.

Abstract: A device for generating a modulation of an optical signal is provided which has a first electro-absorption modulator including a first P-doped semi-conductor area, a first N-doped semi-conductor area, and a first active portion, along with a second electro-absorption modulator including a second P-doped semi-conductor area in electric contact with the first N-doped semi-conductor area, a second N-doped semi-conductor area, and a second active portion, and a connector for introducing electric modulation. In the device, the connector for introducing electric modulation is in contact with the first N-doped semi-conductor area and the second P-doped semi-conductor area.

Abstract: A method and an arrangement of spectrally broadening laser pulses for non-linear pulse compression is disclosed which is based on the transition from the spectral broadening in a waveguide to the spectral broadening in a suitably shaped lens conductor. The arrangement is non-sensitive with respect to the variations of the pulse power, the position and parameters of the laser beam. The spectrally broadened pulses can be compressed in a satisfactory manner and the quality of the laser beam maintained by dividing the non-linear phase required for spectral broadening into sufficiently smaller steps which can be separated without non-linearity by suitable prorogation. The limitation of the pulse powers to less than the critical power of dielectrics is thus overcome and a pulse energy range for which the spectral broadening in the glass fibers cannot be used, is developed. The arrangement can compress pulses having a large average power.

Abstract: A frequency converter system includes a source that emits a beam having a wide spectral band; and a frequency conversion cell including 1) a birefringent nonlinear crystal having a first phase-matching wavelength, with an input face that receives the beam, an output face that emits at least one frequency-converted beam, and at least two parallel faces different from the input and output faces; 2) means for applying an external mechanical force to at least one of said two parallel faces, resulting in a variation in the birefringence of the nonlinear crystal, the value of the applied external mechanical force being determined so as to obtain phase matching at a second phase-matching wavelength different from the first phase-matching wavelength; and 3) means for adjusting the external mechanical force for wavelength tunability in the frequency conversion cell.