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.

An optic-microwave frequency discriminator includes: a fiber coupler receives and combines a first laser and a second laser, than the fiber coupler respectively generates and outputs a first light signal and a second light signal; a photodiode module respectively receives the first light signal and the second light signal, and converts the first light signal into a first microwave signal and converts the second light signal into a second microwave signal; a microwave phase shifter generates a shifted microwave signal by introducing a phase shift to the second microwave signal; a 90° microwave bridge combines the first microwave signal and the shifted microwave signal for generating a first bridge signal and a second bridge signal; a normalized balanced detection module generates an error signal; and a control module generates a controlling voltage signal according to the error signal for tuning a frequency of the second laser.

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 laser device includes element circuits, a front optical system, and a reflective optical system. The front optical system forms a plurality of light beams by collimating a plurality of phase modulated light signals input from the element circuits, and generate a plurality of partially reflected light signals by partially reflecting the plurality of phase modulated light signals. The reflective optical system multiplexes the input local oscillation light with the plurality of partially reflected light signals by reflecting the local oscillation light in a direction of the front optical system. The element circuits can convert each of a plurality of interference light signals generated by multiplexing of the plurality of partially reflected light signals and the local oscillation light into a plurality of electric signals, and can detect a phase error between the plurality of electric signals and a reference signal.

An ultrastable laser system is based on a polarization-maintaining optical fiber. The ultrastable laser system comprises a laser device; acousto-optic modulators, a first beam splitter, a polarizer, an optical fiber interferometer comprising a second beam splitter, an optical fiber delay line, a third acousto-optic modulator, and a beam combiner; a beam combiner, a polarization beam splitter, photoelectric detectors, a frequency synthesizer, frequency mixers, a servo feedback circuit and a piezoelectric ceramic. The temperature interference is eliminated based on the characteristic that refractive indexes of a fast axis and a slow axis of the polarization-maintaining optical fiber differently change with a temperature, a vacuum structure can be avoided, and the ultrastable laser system has low cost, small system, simple structure and high signal stability.

A system for optical comb carrier envelope offset frequency control includes a mode-locked oscillator. The mode-locked oscillator produces an output beam using an input beam and one or more control signals. The output beam includes a controlled carrier envelope offset frequency. A beat note generator produces a beat note signal using a portion of the output beam. A control signal generator produces the one or more control signals to set the beat note signal by modulating the intensity of the input beam within the mode locked oscillator. Modulating the intensity comprises using a Mach-Zehnder intensity modulator or using an intensity modulated external laser to affect a gain medium within the mode-locked laser.

The present disclosure provides embodiments for stabilizing simultaneously N lasers using an optical resonator. A distance between two mirrors forming the optical resonator is adjusted to a stabilization length. More specifically, at the stabilization length, there is, for each of N respective mutually different predetermined frequencies, a resonant frequency of the optical resonator for which the difference between the predetermined frequency and the said resonant frequency is smaller than a predetermined target value. Light from each of the N lasers is fed to the optical resonator and, thereby, N respective error signals are generated. Based on the N error signals, the N lasers are stabilized simultaneously.

A laser device includes element circuits, a front optical system, and a reflective optical system. The front optical system forms a plurality of light beams by collimating a plurality of phase modulated light signals input from the element circuits, and generate a plurality of partially reflected light signals by partially reflecting the plurality of phase modulated light signals. The reflective optical system multiplexes the input local oscillation light with the plurality of partially reflected light signals by reflecting the local oscillation light in a direction of the front optical system. The element circuits can convert each of a plurality of interference light signals generated by multiplexing of the plurality of partially reflected light signals and the local oscillation light into a plurality of electric signals, and can detect a phase error between the plurality of electric signals and a reference signal.

A laser system for amplifying laser light generated from a laser light source and emitting the laser light includes an optical element in an optical path of the laser light and transmits the laser light, a control device to control power to be supplied to the laser system, an imager to capture an image of the optical element, and an image processing circuitry to process the image of the optical element captured by the imager. The image processing circuitry in which reference images of the optical element corresponding to power information relating to the power are prepared in advance includes a comparison unit to compare a captured image of the optical element captured by the imager with a reference image selected by a reference image selection unit, the reference image corresponding to the power information at a time of image capturing by the imager.

Multi-Channels coherent beam combining (CBC) using a mechanism for phase and/or polarization locking that uses a reference optical beam and an array of optical detectors each detector being configured and located to detect overall intensity of an optical interference signal caused by interfering of the reference beam and a beam of the respective channel, where the fast intensity per-channel detection allows simultaneous and quick phase/polarization locking of all channels for improving beam combining system performances.