A laser apparatus includes a light source unit and a light combining unit. The light source unit outputs first laser light and second laser light having a wavelength different from that of the first laser light to different optical paths. The light combining unit is optically coupled to the light source unit, and combines the first laser light and the second laser light to generate a burst pulse with a frequency according to a difference between the wavelength of the first laser light and the wavelength of the second laser light. In the light source unit, the wavelengths of the first laser light and the second laser light are set in advance or settable such that the frequency of the burst pulse is 1 GHz or more.

A laser beam irradiation apparatus including: a plurality of laser light sources emitting first laser beams; and a light-condensing optics system having an incident face on which the first laser beams are made incident and performing an optical operation on the first laser beams to emit second laser beams. The plurality of laser light sources are configured to emit the first laser beams so that beam diameters are expanded towards the incident face. Each first laser beam overlaps at least one of the other laser beams on the incident face. The light-condensing optics system is configured so that beam diameters of second laser beams emitted from the light-condensing optics system are minimal on a target face, and a distance between a center of each second laser beam and the optical axis on the target face is smaller than a beam radius of each second laser beam on the target face.

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 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.

In one embodiment, a lidar system includes a light source configured to emit (i) local-oscillator light and (ii) pulses of light, where each emitted pulse of light is coherent with a corresponding temporal portion of the local-oscillator light. The lidar system also includes a receiver configured to detect the local-oscillator light and a received pulse of light, the received pulse of light including a portion of one of the emitted pulses of light scattered by a target located a distance from the lidar system. The receiver includes a detector configured to produce a photocurrent signal corresponding to the local-oscillator light and the received pulse of light. The photocurrent signal includes a sum of a first term, a second term, and a third term.

In one embodiment, a lidar system includes a light source configured to emit (i) local-oscillator light and (ii) pulses of light. Additionally, the light source is configured to impart a spectral signature of one or more different spectral signatures to each of the emitted pulses of light, where the emitted pulses of light include an emitted pulse of light having a particular spectral signature of the one or more different spectral signatures. The lidar system also includes a receiver configured to detect the local-oscillator light and a received pulse of light, the received pulse of light including a portion of the emitted pulse of light scattered by a target located a distance from the lidar system. The receiver includes a detector configured to produce a photocurrent signal corresponding to the local-oscillator light and the received pulse of light. The receiver also includes a pulse-detection circuit and a frequency-detection circuit.

A master oscillator configured as a seed laser for a laser optical module includes a reduced size, temperature controlled non-planar ring oscillator, a piezo-electric transducer mounted on the non-planar ring oscillator, a pump laser diode, and coupling optics configured to couple a laser output of the pump laser diode to an end face of the non-planar ring oscillator. The pump laser diode may operate as a single-mode pump.

Embodiments discussed herein refer to LiDAR systems and methods that enable substantially instantaneous power and frequency control over fiber lasers. The systems and methods can simultaneously control seed laser power and frequency and pump power and frequency to maintain relative constant ratios among each other to maintain a relatively constant excited state ion density of the fiber laser over time.

A fiber amplifier system including a plurality of seed beam sources each generating a seed beam at a different wavelength and a plurality of fiber amplifiers that amplify the seed beams. The system also includes a spectral beam combining (SBC) grating that spatially combines the amplified beams and directs them in the same direction as an output beam, and a first fiber sampler and a second fiber sampler that generate a first fiber sample beam having a first intensity and a second fiber sample beam having a second intensity. The system further includes a configuration of optical and electrical feedback components that determine a difference between the first intensity and the second intensity and use the difference to control the wavelength of all of the seed beams so that all of the amplified beams are spatially aligned and propagating in the same direction in the output beam.