A high-precision repetition rate locking apparatus for an ultra-fast laser pulse includes: an electronic controlling component comprising: a standard clock, configured to provide a high-precision frequency standard; a pulse generator (PG), configured to provide an electrical pulse signal with adjustable repetition rate, pulse width and voltage magnitude; and a signal generator (SG), connected to the standard clock and the PG, and configured to provide a stable frequency signal for the PG, a phase-shift adjusting component, connected to the electronic controlling component and configured to implement phase modulation through electrically induced refractive index change; a resonant cavity component, comprising a phase shifter, a doped fiber, a laser diode, a wavelength division multiplexer and a reflector, and configured to generate a mode-locked pulse; and a detection system, configured to measure a repetition rate of an output pulse.

A method of generating an optical pulse train using spectral extension by optical phase modulation, spectral narrowing by optical phase demodulation, and narrow linewidth optical filtering is disclosed. It is also described that the wavelength selection of light using a chromatic dispersion element between the optical phase modulator can enrich the method. Systems include an in-line optical setup and a ring-type laser cavity for mode-locked laser outputs. The duration with which the electrical signals driving the modulators are opposed determines the line width of the optical pulses, and the opposite repetition of the electrical signals defines the rate of repetition of an optical pulse train generated. Four different arrangements of electrical signals in the time domain or phase domain make it possible to control the generation of optical pulses and the wavelength selection of the light. (i) A signal arrangement comprising sinusoidal electrical signals with a slight frequency difference. (ii) A signal arrangement comprising a phase-shift between electrical signals. (iii) A signal arrangement comprising a phase-shift between electrical signals depending on the amplitude of the bits. (iv) A signal arrangement comprising random electric waves that repeat themselves over a predefined period to allow the insertion of controllable time delays between each other.

The present invention provides a burst-laser generator using an optical resonator which produces high pulse-strength of burst-laser in order to conduct laser Compton scattering, comprising: a self-oscillation amplifying optical loop-path and an external optical resonator to burst-amplify laser, wherein, laser supplied by an exciting laser source is self-oscillation amplified with the self-oscillation amplifying optical loop-path and further burst-amplified with the external optical resonator.

In this patent, we teach methods to generate coherent X-ray and UUV rays beams for X ray and UUV microscopes using intense femtosecond pulses resulting the Ultra-Supercontinuum (USC) and Higher Harmonic Generation (HHG) from χ3 and χ.sup.5 media produce from electronic and molecular Kerr effect. The response of n.sub.2 (χ3) and n.sub.4 (χ5) at the optical frequency from instantaneously response of carrier phase of envelope results in odd HHG and spectral broadening about each harmonic on the anti-Stokes side of the pump pulse at wo typically in the visible, NIR, and MIR. From the slower molecular Kerr response on femtosecond to picosecond from orientation and molecular motion on n.sub.2 and n.sub.4 which follow the envelope of optical field of the laser gives rise to extreme broadening without HHG. The resulting spectra extend on the Stokes side towards the IR, RF to DC covering most of the electromagnetic spectrum. These HHG and Super broadening covering UUV to X rays and possibly to gamma ray regime for microscopes.

Methods, systems and apparatus are disclosed for delivery of pulsed treatment radiation by employing a pump radiation source generating picosecond pulses at a first wavelength, and a frequency-shifting resonator having a lasing medium and resonant cavity configured to receive the picosecond pulses from the pump source at the first wavelength and to emit radiation at a second wavelength in response thereto, wherein the resonant cavity of the frequency-shifting resonator has a round trip time shorter than the duration of the picosecond pulses generated by the pump radiation source. Methods, systems and apparatus are also disclosed for providing beam uniformity and a sub-harmonic resonator.

In this patent, we teach methods to generate coherent X-ray and UUV rays beams for X ray and UUV microscopes using intense femtosecond pulses resulting the Ultra-Supercontinuum (USC) and Higher Harmonic Generation (HHG) from χ3 and χ.sup.5 media produce from electronic and molecular Kerr effect. The response of n.sub.2 (χ3) and n.sub.4 (χ5) at the optical frequency from instantaneously response of carrier phase of envelope results in odd HHG and spectral broadening about each harmonic on the anti-Stokes side of the pump pulse at wo typically in the visible, NIR, and MIR. From the slower molecular Kerr response on femtosecond to picosecond from orientation and molecular motion on n.sub.2 and n.sub.4 which follow the envelope of optical field of the laser gives rise to extreme broadening without HHG. The resulting spectra extend on the Stokes side towards the IR, RF to DC covering most of the electromagnetic spectrum. These HHG and Super broadening covering UUV to X rays and possibly to gamma ray regime for microscopes.

Methods, systems and apparatus are disclosed for delivery of pulsed treatment radiation by employing a pump radiation source generating picosecond pulses at a first wavelength, and a frequency-shifting resonator having a losing medium and resonant cavity configured to receive the picosecond pulses from the pump source at the first wavelength and to emit radiation at a second wavelength in response thereto, wherein the resonant cavity of the frequency-shifting resonator has a round trip time shorter than the duration of the picosecond pulses generated by the pump radiation source. Methods, systems and apparatus are also disclosed for providing beam uniformity and a sub-harmonic resonator.

A laser system and method. In one example, the laser system includes an optical pulse stretcher configured to stretch pulse durations of an input train of input pulses to produce a train of stretched laser pulses, a pulse replicator module configured to increase a pulse repetition rate of the train of stretched laser pulses to produce a modified pulse train of laser light, a fiber power amplifier configured to amplify the modified pulse train to produce amplified laser pulses, and a pulse compressor that temporally compresses the amplified laser pulses to produce amplified and compressed laser pulses. The system may further include a nonlinear frequency conversion stage comprising at least one nonlinear crystal.

A fiber laser producing a beam of ultrashort laser pulses at a repetition rate greater than 200 MHz includes a linear fiber resonator and a fiber branch. Ultrashort laser pulses are generated by passive mode-locking and circulate within the linear fiber resonator. Each circulating laser pulse is split into a portion that continues propagating in the linear fiber resonator and a complementary portion that propagates through the fiber branch and is then returned to the linear fiber resonator. The optical length of the linear fiber resonator is an integer multiple of the optical length of the fiber branch. The repetition rate of the ultrashort laser pulses is the reciprocal of the propagation time of the laser pulses through the fiber branch.

Methods, systems and apparatus are disclosed for delivery of pulsed treatment radiation by employing a pump radiation source generating picosecond pulses at a first wavelength, and a frequency-shifting resonator having a losing medium and resonant cavity configured to receive the picosecond pulses from the pump source at the first wavelength and to emit radiation at a second wavelength in response thereto, wherein the resonant cavity of the frequency-shifting resonator has a round trip time shorter than the duration of the picosecond pulses generated by the pump radiation source. Methods, systems and apparatus are also disclosed for providing beam uniformity and a sub-harmonic resonator.