Abstract: A Raman fiber laser source (RFLS) is configured with a feeding fiber delivering MM pump radiation to an inner cladding of double-clad MM Raman fiber laser. The MM pump radiation has a sufficient power to produce Raman scattering in the MM Raman fiber converting the pump radiation to a MM signal radiation at a Raman-shifted wavelength ?ram which is longer than a wavelength ?pump of the pump radiation. The RFLS further has a pair of spaced reflectors defining therebetween a resonator for the signal radiation at a 1st Stokes wavelength and flanking at least part of the MM core of the Raman fiber which is provided with a central core region which is doped with impurities for enhancing Raman process. The reflectors and central core region are dimensioned to correspond to the fundamental mode of the MM signal radiation.

Abstract: A pulse configurable laser unit is an environmentally stable, mechanically robust, and maintenance-free ultrafast laser source for low-energy industrial, medical and analytical applications. The key features of the laser unit are a reliable, self-starting fiber oscillator and an integrated programmable pulse shaper. The combination of these components allows taking full advantage of the laser's broad bandwidth ultrashort pulse duration and arbitrary waveform generation via spectral phase manipulation. The source can routinely deliver near-TL, sub-60 fs pulses with megawatt-level peak power. The output pulse dispersion can be tuned to pre-compensate phase distortions down the line as well as to optimize the pulse profile for a specific application.

Abstract: A CPA ultrashort pulse laser system is configured with a beam splitter dividing each ultrashort pulse from a seed laser into at least two replicas which propagate along respective replica paths. Each replica path includes an upstream dispersive element stretching respective replicas to different pulse durations. The optical switches are located in respective replica paths upstream or downstream from upstream dispersive elements. Each optical switch is individually controllable to operate at a high switching speed between “on” and “off” positions so as to selectively block one of the replicas or temporally separate the replicas at the output of the switching assembly. The replicas are so stretched that a train of high peak power ultrashort pulses each are output with a pulse duration selected from a fs ns range and peak power of up to a MW level.

Abstract: The ultra-short pulse chirped pulse amplification (CPA) laser system and method of operating CPA laser system include outputting nearly transform limited (TL) pulses by a mode locked laser. The system and method further include temporarily stretching the TL pulses by a first Bragg grating providing thus each stretched pulse with a chirp which is further compensated for in a second Bragg grating operating as as a compressor. The laser system and method further include a pulse shaping unit measuring a spectral phase across the recompressed pulse and further adjusting the deviation of the measured spectral phase from that of the TL pulse by generating a corrective signal. The corrective signal is applied to the array of actuators coupled to respective segments of one of the BGs which are selectively actuated to induce the desired phase change, with the one BG thus operating as both stretcher/compressor and pulse shaper.

Abstract: A laser system and method. In one example, the laser system includes an optical pulse stretcher configured to stretch pulse durations of an input train of input pulses to produce a train of stretched laser pulses, a pulse replicator module configured to increase a pulse repetition rate of the train of stretched laser pulses to produce a modified pulse train of laser light, a fiber power amplifier configured to amplify the modified pulse train to produce amplified laser pulses, and a pulse compressor that temporally compresses the amplified laser pulses to produce amplified and compressed laser pulses. The system may further include a nonlinear frequency conversion stage comprising at least one nonlinear crystal.

Abstract: A high average and peak power single transverse mode laser system is operative to output ultrashort single mode (SM) pulses in femtosecond-, picosecond- or nanosecond-pulse duration range at a kW to MW peak power level. The disclosed system deploys master oscillator power amplifier configuration (MOPA) including a SM fiber seed, outputting a pulsed signal beam at or near 1030 nm wavelength, and a Yb crystal booster. The booster is end-pumped by a pump beam output from a SM or low-mode CW fiber laser at a pump wavelength in a 1000-1020 nm wavelength range so that the signal and pump wavelengths are selected to have an ultra-low-quantum defect of less than 3%.

Abstract: The ultrafast pulse fiber laser system is configured with scalable output power and operative to reduce degradation of pulse integrity. The disclosed laser system is configured to suppress the pulse distortion through improvement of initial pulse contrast between main and side pulses and improved pulse shape using chirped pulse amplification and a fast intensity modulator driver by a corrected electrical signal that is generated from the original optical signal. The structure providing the improvement includes the photodiode, which is operative to measure the chirped optical pulse and convert it to the electrical signal, and analog electronics that quickly converts the electrical signal to the required signal that suppress the side pulses.

Abstract: A Raman fiber laser source is configured with a feeding fiber delivering MM pump radiation to an inner cladding of double-clad MM Raman fiber laser. The MM pump beam radiation has a sufficient power to produce Raman scattering in the MM Raman fiber converting the pump radiation to a MM signal radiation at a Raman-shifted wavelength ?ram which is longer than a wavelength ?pump of the pump radiation. The Raman laser source further has a pair of spaced reflectors defining therebetween a resonator for the signal radiation at a 1st Stokes wavelength and flanking at least part of the MM core of the Raman fiber which is provided with a central core region which is doped with impurities for enhancing Raman process. The reflectors and central core region are dimensioned to correspond to the fundamental mode of the MM signal radiation which is output from the Raman fiber with an M2 factor ?1.1 and in a power range between a few kW and tens of kW.

Abstract: The ultrafast pulse fiber laser system is configured with scalable output power and operative to reduce degradation of pulse integrity. The disclosed laser system is configured to suppress the pulse distortion through improvement of initial pulse contrast between main and side pulses and improved pulse shape using chirped pulse amplification and a fast intensity modulator driver by a corrected electrical signal that is generated from the original optical signal. The structure providing the improvement includes the photodiode, which is operative to measure the chirped optical pulse and convert it to the electrical signal, and analog electronics that quickly converts the electrical signal to the required signal that suppress the side pulses.

Abstract: The ultra-short pulse chirped pulse amplification (CPA) laser system and method of operating CPA laser system include outputting nearly transform limited (TL) pulses by a mode locked laser. The system and method further include temporarily stretching the TL pulses by a first Bragg grating providing thus each stretched pulse with a chirp which is further compensated for in a second Bragg grating operating as as a compressor. The laser system and method further include a pulse shaping unit measuring a spectral phase across the recompressed pulse and further adjusting the deviation of the measured spectral phase from that of the TL pulse by generating a corrective signal. The corrective signal is applied to the array of actuators coupled to respective segments of one of the BGs which are selectively actuated to induce the desired phase change, with the one BG thus operating as both stretcher/compressor and pulse shaper.

Abstract: A pulse configurable laser unit is an environmentally stable, mechanically robust, and maintenance-free ultrafast laser source for low-energy industrial, medical and analytical applications. The key features of the laser unit are a reliable, self-starting fiber oscillator and an integrated programmable pulse shaper. The combination of these components allows taking full advantage of the laser's broad bandwidth ultrashort pulse duration and arbitrary waveform generation via spectral phase manipulation. The source can routinely deliver near-TL, sub-60 fs pulses with megawatt-level peak power. The output pulse dispersion can be tuned to pre-compensate phase distortions down the line as well as to optimize the pulse profile for a specific application.

Abstract: A single-mode (SM) Green fiber laser is configured to operate in a Green spectral range in a continuous-wave (CW) or quasi-continuous-wave (QCW) mode. The Green laser is configured with a pump source, outputting narrow-linewidth pump light at a fundamental wavelength in one (1) micrometer spectral range, and a single-pass second harmonic generator (SHG), such as a nonlinear LBO crystal, frequency doubling the pump light to output Green light at a signal wavelength. The pump light source is configured to have a MOPFA configuration with a SM seed which emits the SM pump light with a linewidth narrower than 0.2 nm, and at least one ytterbium (“Yb”) fiber amplifier receiving and amplifying the SM pump light at the fundamental wavelength while maintaining the linewidth narrower than 0.2 nm. The SM Green fiber laser operates with a wall plug efficiency between 15% and 30% in a 510-540 nm signal wavelength range and a power range between about 50 W and kW-levels.

Abstract: A high average and peak power single transverse mode laser system is operative to output ultrashort single mode (SM) pulses in femtosecond-, picosecond- or nanosecond-pulse duration range at a kW to MW peak power level. The disclosed system deploys master oscillator power amplifier configuration (MOPA) including a SM fiber seed, outputting a pulsed signal beam at or near 1030 nm wavelength, and a Yb crystal booster. The booster is end-pumped by a pump beam output from a SM or low-mode CW fiber laser at a pump wavelength in a 1000-1020 nm wavelength range so that the signal and pump wavelengths are selected to have an ultra-low-quantum defect of less than 3%.

Abstract: A single mode fiber pulsed oscillator includes an all normal dispersion ring cavity provided with a mode-locking fiber loop component and a giant chirp generating fiber component. The mode-locking fiber loop component is configured with a hybrid of NOLM and NALM configurations which is operative to induce a first phase acquisition of a spectrally narrow pulse due to SPM. The giant chirp generating fiber loop component is configured to induce the additional phase acquisition to the pulse broadened in the mode-locking fiber component so as to generate a pulse with a giant chirp. The fiber loop components each include a fiber amplifier and a coil of fiber. The amplifiers each are configured with an active fiber provided with a core which supports multiple transverse mode in a range of wavelength except for the desired wavelength at which the core is configured to support a single fundamental mode.

Abstract: A single-mode (SM) Green fiber laser is configured to operate in a Green spectral range in a continuous-wave (CW) or quasi-continuous-wave (QCW) mode. The Green laser is configured with a pump source, outputting narrow-linewidth pump light at a fundamental wavelength in one (1) micrometer spectral range, and a single-pass second harmonic generator (SHG), such as a nonlinear LBO crystal, frequency doubling the pump light to output Green light at a signal wavelength. The pump light source is configured to have a MOPFA configuration with a SM seed which emits the SM pump light with a linewidth narrower than 0.2 nm, and at least one ytterbium (“Yb”) fiber amplifier receiving and amplifying the SM pump light at the fundamental wavelength while maintaining the linewidth narrower than 0.2 nm. The SM Green fiber laser operates with a wall plug efficiency between 15% and 30% in a 510-540 nm signal wavelength range and a power range between about 50 W and kW-levels.

Abstract: A pulsed fiber generator is configured with a unidirectional ring waveguide configured to emit a train of pulses. The ring waveguide includes multiple fiber amplifiers, chirping fiber components coupled to respective outputs of first and second fiber amplifiers, and multiple spectral filters coupled to respective outputs of the chirping components. The filters have respective spectral band passes centered around different central wavelengths so as to provide leakage of light along the ring cavity in response to nonlinear processes induced in the ring cavity. The pulse generator operates at a preliminary stage during which it is configured to develop a pitch to a signal, and at a steady stage during which it is configured to output a train of pulses through an output coupler at most once per a single round trip of the signal.

Abstract: An RGB light source for a luminaire projector system includes Red, Green and Blue lasers each outputting a randomly polarized (RP) single mode (SM) light with at least a 4 nm spectral linewidth. The Green laser has a MOPFA-structured pump which outputs a pulsed pump beam at a fundamental wavelength in a 1 ?m wavelength range and further includes a SHG. The SHG includes an LBO nonlinear crystal receiving the pulsed pump beam and outputting a train of pulses of BB Green light. The Red laser is configured with a QCW fiber laser pump and a frequency converter with an LBO nonlinear crystal outputting a train of pulses of red light in a 6xx nm wavelength range.

Abstract: An RGB light source for a luminaire projector system includes Red, Green and Blue lasers each outputting a randomly polarized (RP) single mode (SM) light with at least a 4 nm spectral linewidth. The Green laser has a MOPFA-structured pump which outputs a pulsed pump beam at a fundamental wavelength in a 1 ?m wavelength range and further includes a SHG. The SHG includes an LBO nonlinear crystal receiving the pulsed pump beam and outputting a train of pulses of BB Green light. The Red laser is configured with a QCW fiber laser pump and a frequency converter with an LBO nonlinear crystal outputting a train of pulses of red light in a 6xx nm wavelength range.

Abstract: A broad line red light generator is configured with a single mode (SM) pulsed ytterbium (“Yb”) fiber laser pump source outputting pump light in a fundamental mode (“FM”) at a pump wavelength which is selected from a 1030-1120 nm wavelength range. The disclosed generator further includes a SM fiber Raman converter spliced to an output of the Yb fiber laser pump source. The Raman converter induces an “n” order frequency Stokes shift of the pump light to output the pump light at a Raman-shifted wavelength within 1220 and 1300 nm wavelength range with a broad spectral line of at least 10 nm. The disclosed light generator further has a single pass second harmonic generator (“SHG”) with a lithium triborate (“LBO”) nonlinear optical crystal having a spectral acceptance linewidth which is sufficient to cover the broad spectral line of the pump light. The SHG generates a SM pulsed broad-line red light with a broad spectral line of at least 4 nm.

Abstract: The inventive system for crystallizing an amorphous silicon (a-Si) film is configured with a quasi-continuous wave fiber laser source operative to emit a film irradiating pulsed beam. The fiber laser source is operative to emit a plurality of non-repetitive pulses incident on the a-Si. In particular, the fiber laser is operative to emit multiple discrete packets of film irradiating light at a burst repetition rate (BRR), and a plurality of pulses within each packet emitted at a pulse repetition rate (PRR) which is higher than the BRR. The pulse energy, pulse duration of each pulse and the PRR are controlled so that each packet has a desired packet temporal power profile (W/cm2) and packet energy sufficient to provide transformation of a-Si to polysilicon (p-Si) at each location of the film which is exposed to at least one packets.