A wavelength-stabilised narrow-linewidth mode-locked picosecond laser system comprises a laser cavity which includes an amplifier, a mode-locking element, and a fiber Bragg grating which acts as a narrowband reflector. The system includes a mount to which the fiber Bragg grating is mounted under tension, a tension control system to adjust the tension, and a measurement device to provide a measurement output related to a current operating wavelength of the fiber Bragg grating. A microcontroller or other controller wavelength-stabilises the laser by controlling the tension control system responsive to the measured wavelength.

A wavelength-stabilised narrow-linewidth mode-locked picosecond laser system comprises a laser cavity which includes an amplifier, a mode-locking element, and a fiber Bragg grating which acts as a narrowband reflector. The system includes a mount to which the fiber Bragg grating is mounted under tension, a tension control system to adjust the tension, and a measurement device to provide a measurement output related to a current operating wavelength of the fiber Bragg grating. A microcontroller or other controller wavelength-stabilises the laser by controlling the tension control system responsive to the measured wavelength.

A fiber laser device includes: a housing; a first optical element configured to include a first fiber and a first fiber connector; and a second optical element configured to include a second fiber and a second fiber connector. The first optical element and the second optical element are optically connectable via the first fiber connector and the second fiber connector, at least a part of the first optical element is housed in a module housing, an opening is formed in a wall portion of the housing, the module housing is detachably attached inside the housing through the opening, and the end portion of the first fiber and the first fiber connector are provided to project from the module housing at one end portion of the module housing.

The invention relates to an apparatus for generating temporally spaced apart light pulses, comprising a first laser (11) which generates a first sequence (I) of light pulses at a first repetition rate, a second laser (12) which generates a second sequence (II) of light pulses at a second repetition rate, and at least one actuating member which influences the first repetition rate and/or the second repetition rate. It is an object of the invention to provide an apparatus for generating temporally spaced apart light pulses which is improved in relation to the prior art. This object is achieved by the invention by a control element (23) which applies a periodic modulation signal (24) to the actuating member for periodic variation of the first repetition rate and/or the second repetition rate, wherein the actuating member comprises a mechanical oscillator excited by the modulation signal (24), the deflection of said oscillator causing an adjustment in the resonator length of the first laser (11) and/or second laser (12), wherein the mechanical oscillator oscillates in resonant fashion at the frequency of the modulation signal (24). In accordance with the invention, an actuator (e.g. a piezo-actuator) which adjusts the resonator length of the laser is operated in resonant fashion. As a result, a large maximum time offset of the light-pulse sequences (I, II) with, at the same time, a high scanning speed is rendered possible. Moreover, the invention relates to a method for generating temporally spaced apart light pulses.

A laser utilizes a cavity design which allows the stable generation of high peak power pulses from mode-locked multi-mode fiber lasers, greatly extending the peak power limits of conventional mode-locked single-mode fiber lasers. Mode-locking may be induced by insertion of a saturable absorber into the cavity and by inserting one or more mode-filters to ensure the oscillation of the fundamental mode in the multi-mode fiber. The probability of damage of the absorber may be minimized by the insertion of an additional semiconductor optical power limiter into the cavity.

The present invention relates to a frequency comb article includes an oscillator; a fiber amplifier; a frequency doubler; a nonlinear fiber; and an interferometer, wherein the fiber amplifier and the nonlinear fiber include a polarization maintaining fiber, and the oscillator, frequency doubler, and interferometer are entirely polarization maintaining.

A method of performing coherent anti-stokes Raman spectroscopy (CARS) includes generating first and second optical pulse trains having different and adjustable repetition rates. One of the pulse trains is directed in a CW direction and the other in a CCW direction. A frequency shift and a first linear chirp is applied to optical pulses in the first optical pulse train. A second linear chirp is applied to optical pulses in the second optical pulse train. The first and second linear chirps having a common chirp rate. One of the chirped optical pulse trains is used as a pump beam and the other is used as a Stokes beam. The first and second chirped optical pulse trains are combined to define a combined beam. The combined beam is provided to a CARS spectroscopic system for exciting a resonant mode in a sample and generating a CARS signal.

The present invention discloses a high-repetition-rate fiber laser having an ultrashort resonant cavity with a tunable repetition rate, including a pump source, a wavelength division multiplexer, an optical isolator, and an ultrashort resonant cavity with a tunable repetition rate. The wavelength division multiplexer is configured to couple pump light generated by the pump source into the ultrashort resonant cavity with a tunable repetition rate and output generated signal light to the outside of the ultrashort resonant cavity with a tunable repetition rate, and the optical isolator is connected to the wavelength division multiplexer. The ultrashort resonant cavity with a tunable repetition rate includes a first graded-index lens, a second graded-index lens, a ferrule, a sleeve tube, a gain fiber, a semiconductor saturable absorber mirror, and a dielectric film.

The present invention discloses a high-repetition-rate fiber laser having an ultrashort resonant cavity with a tunable repetition rate, including a pump source, a wavelength division multiplexer, an optical isolator, and an ultrashort resonant cavity with a tunable repetition rate. The wavelength division multiplexer is configured to couple pump light generated by the pump source into the ultrashort resonant cavity with a tunable repetition rate and output generated signal light to the outside of the ultrashort resonant cavity with a tunable repetition rate, and the optical isolator is connected to the wavelength division multiplexer. The ultrashort resonant cavity with a tunable repetition rate includes a first graded-index lens, a second graded-index lens, a ferrule, a sleeve tube, a gain fiber, a semiconductor saturable absorber mirror, and a dielectric film.

A system for generating a visible-to-mid-infrared frequency comb, including an all polarization-maintaining fiber-based frequency comb module and an optical frequency comb spectral expansion module. The all polarization-maintaining fiber-based frequency comb module is configured to generate a laser with evenly spaced and coherent frequencies and spectral lines. The optical frequency comb spectral expansion module is configured to perform spectral expansion on the laser to output the visible-to-mid-infrared frequency comb. The optical frequency comb spectral expansion module includes an amplifier, a 90:10 beam splitter, a first all polarization-maintaining compression fiber, a second all polarization-maintaining compression fiber, a 1100 nm-2350 nm supercontinuum unit and a 500 nm-1100 nm supercontinuum unit. A circuit of a semiconductor laser diode unit is configured to control output of the 1100 nm-2350 nm laser.