A frequency comb laser providing large comb spacing is disclosed. At least one embodiment includes a mode locked waveguide laser system. The mode locked waveguide laser includes a laser cavity having a waveguide, and a dispersion control unit (DCU) in the cavity. The DCU imparts an angular dispersion, group-velocity dispersion (GVD) and a spatial chirp to a beam propagating in the cavity. The DCU is capable of producing net GVD in a range from a positive value to a negative value. In some embodiments a tunable fiber frequency comb system configured as an optical frequency synthesizer is provided. In at least one embodiment a low phase noise micro-wave source may be implemented with a fiber comb laser having a comb spacing greater than about 1 GHz. The laser system is suitable for mass-producible fiber comb sources with large comb spacing and low noise. Applications include high-resolution spectroscopy.

The invention relates to an apparatus for generating laser pulses. It is an object of the invention to provide a method for generating synchronized laser pulse trains at variable wavelengths (e.g., for coherent Raman spectroscopy/microscopy), wherein the switching time for switching between different wavelengths should be in the sub-μs range. For this purpose the apparatus according to the invention comprises a pump laser (1), which emits pulsed laser radiation at a specified wavelength, an FDML laser (3), which emits continuous wave laser radiation at a cyclically variable wavelength, and a nonlinear conversion medium (4), in which the pulsed laser radiation of the pump laser (1) and the continuous wave laser radiation of the FDML laser (3) are superposed. In the nonlinear conversion medium (4) the pulsed laser radiation of the pump laser (1) and the continuous wave laser radiation of the FDML laser (3) are converted in an optical parametric process into pulsed laser radiation at a signal wavelength and an idler wavelength that differs therefrom. Furthermore the invention relates to a method for generating laser pulses.

Chirped pulse amplification (CPA) systems configured to generate and amplify multi-pulses are described. The nonlinear interaction of pulses can generate a multiple pulse pack with a dense time separation between pulses. Reducing or eliminating the nonlinear interaction can be provided by spectrally and/or temporally splitting pulses in the chirped amplification system.

A laser architecture for selectively producing short high-energy laser pulses having octave-spanning, continuous tunability. Two oppositely chirped pulses are used in combination with a pair of tunable pulse stretcher/compressors to produce a short, high-energy, tunable, broadband pulse.

The invention relates to a device for generating temporally spaced light pulses. Said device comprises a first light source which emits a first train of light pulses, a second light source which emits a second train of light pulses, and a phase-locked loop which regulates the relative phase of the light-pulse trains towards a target value. When the two light-pulse trains each pass through an optical transmission path to an application site that is spatially remote from the light sources, fluctuating phase differences in the light-pulse trains at the application site occur due to external influences along the transmission paths. The object of the invention is to provide an improved device for generating temporally spaced light pulses. In particular, the above-mentioned fluctuating phase differences are intended to be prevented. To do this, the invention proposes a detection apparatus that interacts with the phase-locked loop and detects a phase difference in the light-pulse trains at the application site caused by propagation-time differences along the transmission paths. In particular, the phase difference in the light-pulse trains at the application site is derived from light pulses that are reflected from the application site and pass through the transmission paths in the return direction. The detected phase difference can then be compensated for by the existing regulation of the relative phase of the light-pulse trains. In addition, the invention relates to a method for generating temporally spaced light pulses.

This invention provides a device for improving laser wavelength conversion efficiency and a laser system configured to provide high-power multi-wavelength femtosecond laser pulses using the device. The device for improving laser wavelength conversion efficiency comprises a wavelength conversion member photonic crystal fiber (PCF), wherein the device for improving laser wavelength conversion efficiency improves wavelength conversion efficiency by shortening the length of the PCF. The device provided in this invention not only reduces the attenuation and dispersion caused by the optical fiber, but also improves the energy conversion efficiency within a specific wavelength range. The use of the technique not only increases the energy of light pulse, but also greatly reduces the amount of fiber used, and can maximize the energy of the desired wavelength according to experimental requirements when using laser input sources of different wavelengths.

An integrated Fourier domain mode-locked optoelectronic oscillator and its application and a communication system are provided, which relates to the technical field of microwave photonics. The integrated Fourier domain mode-locked optoelectronic oscillator includes an optoelectronic chip and an electronic chip. The optoelectronic chip includes a laser, a modulator, an optical notch filter, and a photodetector coupled via an optical waveguide. The electronic chip includes an electrical amplifier and a power splitter coupled via a coplanar microwave waveguide. The volume, weight and power consumption of the Fourier domain mode-locked optoelectronic oscillator is greatly reduced by integrating all the devices on the chip. A tunable sweeping microwave signal output is realized, and the sweeping speed of the output signal is increased. The integrated Fourier domain mode-locked optoelectronic oscillator can be used in radars and communication systems.

Disclosed is a frequency swept source apparatus including a mode locking laser that outputs an input optical signal having first to n-th frequency components, a transmission delay controller that generates first to m-th sub-optical signals, each of which includes at least one component of the first to n-th frequency components, and outputs a delay optical signal obtained by sequentially delaying the first to m-th sub-optical signals. The transmission delay controller includes a demultiplexer that outputs the first to m-th sub-optical signals to first to m-th channels based on the input optical signal, respectively, a path delay unit that adjusts lengths of optical paths of the first to m-th channels so as to be different from one another, a refractive index controller that adjusts a refractive index of each of the first to m-th channels, and a multiplexer that combines the first to m-th sub-optical signals.

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.

Apparatuses and methods are disclosed for applying laser energy having desired pulse characteristics, including a sufficiently short duration and/or a sufficiently high energy for the photomechanical treatment of skin pigmentations and pigmented lesions, both naturally-occurring (e.g., birthmarks), as well as artificial (e.g., tattoos). The laser energy may be generated with an apparatus having a resonator with the capability of switching between a modelocked pulse operating mode and an amplification operating mode. The operating modes are carried out through the application of a time-dependent bias voltage, having waveforms as described herein, to an electro-optical device positioned along the optical axis of the resonator.