A light source employed in a coherent Raman scattering (CRS) spectroscopic apparatus or a CRS microscope includes a chromium forsterite laser (CrFL), a variable delay optical path configured to delay one optical pulse of branched optical pulses obtained by dividing an optical pulse from the CrFL according to a power, a highly nonlinear waveguide into which the other optical pulse of the branched optical pulses is input, a first wavelength filter connected to an output of the highly nonlinear waveguide, an ytterbium-doped glass fiber optical amplifier (YbFA) connected to an output of the wavelength filter, and a second wavelength filter connected to an output of the YbFA. The light source includes a one-optical path mode in which two wavelength bands corresponding to Raman scattering wavenumbers to be used for measurement are selected from an output of the variable delay optical path, and a two-optical path mode in which an output of the variable delay optical path and an output of the second wavelength filter are time-synchronized.

Binary-phase-shift-key, phase-modulated waveforms with gigahertz bandwidths, suitable for kilowatt-class fiber amplifiers, can be narrowed back to the source laser’s linewidth via second-harmonic, sum-frequency, or difference-frequency generation in a second-order nonlinear crystal. The spectrum of an optical signal phase-modulated with a pseudo-random bit sequence (PRBS) waveform recovers its original optical spectrum when frequency-doubled using second-harmonic generation (SHG). Conceptually, the PRBS waveform is cancelled by the SHG process, and the underlying laser spectrum is converted to the second-harmonic wavelength as though the PRBS modulation were not present. The same cancellation is possible with sum-frequency generation (SFG) and difference frequency generation (DFG), making it possible to construct high-power, narrow-linewidth lasers at wavelengths from the visible to the long-wave infrared. Using ytterbium-, erbium-, thulium-, and neodymium-doped fibers with SHG, SFG and DFG processes allows generation of high-power beams with very narrowband optical spectra and wavelengths from below 400 nm to beyond 5 .Math.m.

The present disclosure provides an ultrafast laser that outputs multiple wavelengths. The ultrafast laser includes a fundamental frequency ultrafast laser unit, an optical beam splitting and polarization controlling unit, a multiple frequency unit, and an optical beam combining unit. The fundamental frequency ultrafast laser generates a multiple frequency ultrafast laser by the multiple frequency unit, such as double frequency light, triple frequency light, etc., and the optical beam combining unit makes the fundamental frequency light and the double frequency light output in a light outlet, the controlling unit controls the wavelength of the laser of the light outlet by controlling the polarization state of the laser. The ultrafast laser of the present disclosure can realize fast switching output among the fundamental frequency light and multiple frequency light, and output of combined pulse fundamental frequency light and double frequency light. The present disclosure also provides a strong powerful laser tool.

Some implementations described herein provide a laser device. The laser device includes a first portion of the laser device, at a proximal end of the laser device, that includes one or more optical devices, where the first portion is configured to emit first electromagnetic waves having a first wavelength. The laser device includes a second portion of the laser device, at a distal end of the laser device, that includes an optical crystal configured to receive the first electromagnetic waves and to emit second electromagnetic waves having a second wavelength based on reception of the first electromagnetic waves, where the optical crystal includes a thin film coating disposed on an end of the optical crystal, the thin film coating configured to: support emission of the second electromagnetic waves from the optical crystal, and support internal reflection of the first electromagnetic waves within the optical crystal.

A laser transmitter including a waveform controller arranged to generate a waveform script having at least one of a pulse repetition frequency setting, a pulse duration setting, and a pulse amplitude pre-warp setting. The transmitter also includes an optical waveform generator arranged to: i) receive the waveform script, ii) generate pre-warped signal pulses based on the waveform script to compensate for gain distortion effects of a laser power amplifier, and iii) output the pre-warped signal pulses. The laser power amplifier is arranged to: i) receive the pre-warped signal pulses, ii) receive a continuous wave signal, and iii) output amplified signal pulses that maintain a substantially constant drive intensity at the input of a non-linear wavelength converter. The non-linear wavelength converter is arranged to receive the amplified signal pulses and emit wavelength-converted pulses.

A current control device supplies a current to a semiconductor laser in order to output laser light to the semiconductor laser, and includes a current commander and a supplier. The current commander outputs a command value corresponding to a current value by increasing the command value with a lapse of time until reaching a target command value corresponding to a current value for outputting the laser light with a predetermined strength. The supplier supplies a current with a size corresponding to the command value output by the current commander to the semiconductor laser.

A broadband light source device for creating broadband light pulses includes a hollow-core fiber and a pump laser source device. The hollow-core fiber is configured to create the broadband light pulses by an optical non-linear broadening of pump laser pulses. The hollow-core fiber includes a filling gas, an axial hollow light guiding fiber core configured to support core modes of a guided light field, and an inner fiber structure surrounding the fiber core and configured to support transverse wall modes of the guided light field. The pump laser source device is configured to create and provide the pump laser pulses at an input side of the hollow-core fiber. The transverse wall modes include a fundamental transverse wall mode and second and higher order transverse wall modes.

A mode control system and method for controlling an output mode of a broadband radiation source including a photonic crystal fiber (PCF). The mode control system includes at least one detection unit configured to measure one or more parameters of radiation emitted from the broadband radiation source to generate measurement data, and a processing unit configured to evaluate mode purity of the radiation emitted from the broadband radiation source, from the measurement data. Based on the evaluation, the mode control system is configured to generate a control signal for optimization of one or more pump coupling conditions of the broadband radiation source. The one or more pump coupling conditions relate to the coupling of a pump laser beam with respect to a fiber core of the photonic crystal fiber.

A steerable laser transmitter and situational awareness sensor uses a liquid crystal waveguide (LCWG) to steer a spot-beam onto a conical mirror, which in turn redirects the spot-beam to scan a FOV. The spot-beam passes through one or more annular sections of non-linearly material (NLM) formed along the axis and around the conical mirror. Each NLM section converts the wavelength of the spot-beam to a different wavelength while preserving the steering of the spot-beam. The LCWG may shape or move the spot-beam along the axis of the conic mirror to sequentially, time or time and spatially multiplex the spot-beam between the original and different wavelengths. This provides multispectral capability from a single laser source. The transmitter also supports steering the spot-beam at a wavelength at which the LCWG cannot steer directly.

An ophthalmic illumination system includes a light source to emit a light beam and a filter comprising a clear region to transmit visible light in the visible spectrum and a first filtered region to transmit visible light in a first spectral range. The filter is arranged within the optical path of the beam. The system includes a plurality of chromaticity sensors to receive a portion of the light beam transmitted by the filter and output a signal indicating chromaticity of the received beam. The system also includes a processor to receive the signal indicating chromaticity, compare the indicated chromaticity to a target chromaticity stored in memory and, based on the comparison, adjust the chromaticity of the light beam transmitted by the filter by generating a signal to move the filter from a first position in which the light beam is incident upon only the clear region to a second position in which the light beam is partially incident on both the clear region and the first filtered region.