A laser amplifier capable of achieving a high output by offsetting distortion of an amplified laser beam. The laser amplifier includes: first and second amplification media which amplify a penetrating laser beam; a pre-compensation lens unit which pre-compensates for a laser beam irradiated to the first amplification medium so as to offset a thermal lensing effect generated in the first amplification medium and the second amplification medium; a first polarizing and penetrating mirror inclined to the laser beam irradiated to a front end of the first amplification medium and allowing a laser beam that vibrates in a specific direction to penetrate and reflecting a laser beam that vibrates in another direction; a polarization conversion plate provided at a rear side of the second amplification medium and changing a vibration direction of the laser beam penetrating the second amplification medium; and a first reflection mirror for reflecting a laser beam.

Apparatus and methods for producing ultrashort optical pulses are described. A high-power, solid-state, passively mode-locked laser can be manufactured in a compact module that can be incorporated into a portable instrument. The mode-locked laser can produce sub-50-ps optical pulses at a repetition rates between 200 MHz and 50 MHz, rates suitable for massively parallel data-acquisition. The optical pulses can be used to generate a reference clock signal for synchronizing data-acquisition and signal-processing electronics of the portable instrument.

A laser including a solid state laser gain medium having a D-shaped cross section and an unstable resonator laser cavity including the solid state laser gain medium configured with a geometric magnification in a range of 1 to 5 under the intended operating conditions, including the effects of thermal lensing in the gain medium. An optical switching device in the unstable resonator laser cavity generates a pulse duration in the range of 0.05 to 100 nanoseconds. A diode-pump source is configured to inject pump light through the curved or barrel surface of the D-shaped gain medium.

An optical arrangement includes a disk-shaped laser-active medium configured to create an optical gain upon being pumped within a pump volume, and a laser beam incoupler for input coupling a laser beam as a seed laser beam into the laser-active medium. The laser beam interacts with the laser-active medium. The optical arrangement further includes an auxiliary resonator for creating an auxiliary resonator radiation field. The auxiliary resonator radiation field interacts with the laser-active medium. The auxiliary resonator is configured to suppress at least one mode of the auxiliary resonator radiation field that overlaps with at least one mode of the laser beam in the pump volume.

A device includes: at least one laser element with light emitting points to output fundamental waves in a one-dimensional array; a wavelength converting element to carry out wavelength conversion of the incident fundamental waves, and to output wavelength converted light rays; and an output mirror to reflect the fundamental waves, and to transmit the wavelength converted light rays resulting from the wavelength conversion by the wavelength converting element. The wavelength converting element is disposed between the laser element and the output mirror, and the distance between the position of a waist of the fundamental waves output from the laser element and the output mirror is set in accordance with a Talbot condition under which the adjacent light emitting points cause phase synchronization with each other.

The present invention provides a rotating chalcogenide gain media ring to provide un-precedented power generation with minimal thermal lensing for CW lasing in the mid-IR spectrum.

The invention relates to an optical waveguide (3) as a laser medium or as a gain medium for high-power operation, wherein the optical waveguide (3) is an optical fiber, the light-guiding core of which, at least in sections, is doped with rare earth ions. It is an object of the invention to provide an optical waveguide as a laser or a gain medium, and a laser/amplifier combination realized therewith, in which the output signal of the laser or gain medium is better stabilized. The invention achieves this object by virtue of the maximum small signal gain of the optical waveguide (1) being up to 60 dB, preferably up to 50 dB, more preferably up to 40 dB, even more preferably up to 30 dB, on account of the concentration of the rare earth ions and/or the distribution thereof in the light-guiding core. Moreover, the invention relates to the use of such an optical waveguide as an amplifier fiber (3) in a laser/amplifier combination.

Systems and methods are described for producing an amplitude-modulated laser pulse train. The laser pulse train can be used to cause fluorescence in materials at which the pulse trains are directed. The parameters of the laser pulse train are selected to increase fluorescence relative to a constant-amplitude laser pulse train. The amplitude-modulated laser pulse trains produced using the teachings of this invention can be used to enable detection of specific molecules in applications such as gene or protein sequencing.

A laser system includes a multipass amplifier for amplifying laser light and providing an amplified output beam, and a control unit. The multipass amplifier includes a laser-active medium. The control unit is configured to keep a thermal load on the laser-active medium substantially constant over a range of a laser output power of the output beam. The thermal load is determined by at least two different power sources.

A converging thermal lens is transiently formed by directing a shaped pulsed light beam having at least a first wavelength to a thermo-optic material, whereby the thermo-optic material absorbs the light beam and experiences local heating in response thereto. The heating induces a refractive index profile in the thermo-optic material that temporarily forms the converging thermal lens. In some embodiments, the refractive index of the thermo-optic material has a negative temperature dependence, and the pulsed light beam is shaped to have an inverted light pattern with a maximum intensity in an outer region of the beam cross-section. Alternatively, in some embodiments, the refractive index of the thermo-optic material has a positive temperature dependence, and the pulsed light beam is shaped to have a radially-varying light pattern with a maximum intensity in a central region of the beam cross-section.