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.

An apparatus includes: abeam splitter on abeam path, the beam splitter configured to receive light from a deep ultraviolet (DUV) light source; and a first plurality of reflective optical elements on the beam path. The beam splitter is configured to direct a portion of the light received from the DUV light source toward the first plurality of reflective optical elements; the first plurality of reflective optical elements is configured to rotate a divergence of the portion of the light to produce rotated light; and the beam splitter is configured to direct the rotated light and a portion of the light received from the DUV light source onto an output beam path.

A WDM seed beam source for a fiber laser amplifier system that includes a number of master oscillators that generate seed beams at different wavelengths and a spectral multiplexer that multiplexes all of the seed beams onto a single fiber. An EOM modulates the combined seed beams on the single fiber and a spectral demultiplexer then separates the modulated seed beams into their constituent wavelengths on separate fibers before the seed beams are amplified and spectrally combined. The fiber laser amplifier system includes a separate fiber amplifier that amplifies the separated seed beams, an emitter array that directs the amplified beams into free space, beam collimating optics that focuses the uncombined beams, and an SBC grating responsive to the collimated uncombined beams that spatially combines the collimated uncombined beams.

A hybrid coherent beam combining (CBC) and spectral beam combining (SBC) fiber laser amplifier system including a beam shaper array assembly and a beam source that provides a plurality of beams having a low fill factor profile. The assembly includes an input beam shaper array having a plurality of rectilinear input cells positioned adjacent to each other that are shaped to cause the beam to expand as it propagates away from the input array to be converted from the low fill factor profile to a high fill factor profile. The assembly further includes an output beam shaper array having a plurality of output cells positioned adjacent to each other that are shaped to cause the beam to stop expanding so that the output array provides a plurality of adjacent beams with minimal overlap and a minimal gap between the beams.

A method for fabricating a beam shaper array assembly, where the beam shaper array assembly changes the shape of a plurality of beams. The method includes providing an optical endcap having a plurality of connector stems, welding a fiber to each of the stems to form an emitter array and positioning a beam shaper array adjacent to the endcap opposite to the stems. The method also includes measuring an angle error and a position error of each fiber, calculating a correction for each fiber for the angle error and the position error and correcting the angle and position of each fiber using the calculated corrections.

A fiber laser amplifier system including a non-linear fiber amplifier receiving a seed beam and a pump beam, where the amplifier amplifies the seed beam using the pump beam to provide an output beam having a carrier spectrum. A beam sampler samples off a sample beam from the output beam, a filter receives the sample beam and filters out the carrier spectrum from the sample beam, a photodetector detects beam power of the filtered sample beam and provides a beam power signal, and a controller receives the beam power signal, where the controller controls one or more of an FM drive signal, an AM drive signal and a pump beam to change seed beam FM modulation, seed beam AM modulation and/or pump power in a manner that reduces the beam power of the filtered sample beam and thus beam power outside of the carrier spectrum.

A system includes a signal seeder configured to generate a pulsed seed signal, where the signal seeder includes a master oscillator configured to generate an optical signal at a first wavelength. The system also includes a series of optical preamplifiers collectively configured to amplify the pulsed seed signal and generate an amplified signal. The system further includes a Raman fiber amplifier configured to amplify the amplified signal and generate a Raman-shifted amplified signal. The Raman fiber amplifier is configured to shift a wavelength of the amplified signal to a second wavelength different than the first wavelength during generation of the Raman-shifted amplified signal.

A coherently beam combining (CBC) fiber laser amplifier system including beam shaper array assembly and a beam source that provides a plurality of beams having a low fill factor profile. The assembly includes an input beam shaper array having a plurality of input cells positioned adjacent to each other that are shaped to cause the beam to expand as it propagates away from the input array to be converted from the low fill factor profile to a high fill factor profile and cause the profile to taper to a lower value at a perimeter of each input array cell. The assembly further includes an output beam shaper array having a plurality of output cells positioned adjacent to each other that are shaped to cause the beam to stop expanding so that the output array provides a plurality of adjacent beams with minimal overlap and a minimal gap between the beams.

A spectral beam combining (SBC) fiber laser amplifier system including a beam shaper array assembly and a beam source that provides a plurality of beams having a low fill factor profile. The assembly includes an input beam shaper array having a plurality of input cells positioned adjacent to each other that are shaped to cause the beams to expand as they propagates away from the input array to be converted from the low fill factor profile to a high fill factor profile and be tapered to a lower value at a perimeter of each input array cell. The assembly further includes an output beam shaper array having a plurality of output cells positioned adjacent to each other that are shaped to cause the beams to stop expanding so that the output array provides a plurality of adjacent beams with minimal overlap and a minimal gap between the beams.

A method of controlling an optical transmitter includes steps of amplifying, by an EDFA, a main signal output from an optical modulator, attenuating and outputting, by a VOA, the main signal amplified and output by the EDFA, and maintaining an output power of the main signal output from the VOA at a predetermined value, suspending the phase modulation in the optical modulator to output continuous wave light from the optical modulator, disabling feedback control of the VOA that is performed by the VOA controller and maintaining a constant control signal of the VOA, disabling feedback control of a pump laser that is performed by a pump laser controller, and controlling the pump laser to modulate an intensity of the excitation light and generate an auxiliary signal having a cycle longer than a cycle of the main signal.