A system includes an optical source configured to emit a pulsed light beam, the optical source comprising one or more chambers, each of the one or more chambers configured to hold a gaseous gain medium, the gaseous gain medium being associated with an assumed gas life; at least one detection module configured to: receive and analyze data related to the pulsed light beam, and produce a beam quality metric based on the data related to the pulsed light beam; and a monitoring module configured to: analyze the beam quality metric, determine a health status of the gaseous gain medium based on the analysis of the beam quality metric, and produce a status signal based on the determined health status, the status signal indicating whether to extend use of the gaseous gain medium beyond the assumed gas life or to end use of the gaseous gain medium.

Methods, systems, and devices are disclosed for divided-pulse lasers. In one aspect, a pulsed laser is provided to include a laser cavity including an optical amplifier and a plurality of optical dividing elements and configured to direct a laser pulse of linearly polarized light into the plurality of optical dividing elements to divide the light of the laser pulse into a sequence of divided pulses each having a pulse energy being a portion of the energy of the laser pulse before entry of the optical dividing elements, to subsequently direct the divided pulses into the optical amplifier to produce amplified divided pulses. The laser cavity is configured to direct the amplified divided pulses back into the plurality of optical dividing elements for a second time in an opposite direction to recombine the amplified divided pulses into a single laser pulse with greater pulse energy as an output pulse of the laser cavity.

In one embodiment, a laser system includes a seed laser diode configured to produce a free-space seed-laser beam and a seed-laser focusing lens configured to focus the seed-laser beam. The laser system also includes a semiconductor optical amplifier (SOA) that includes a front facet, a back facet, and a waveguide extending from the front facet to the back facet. The SOA is configured to: receive, at the front facet, light from the focused seed-laser beam; amplify the received light as the received light propagates along the SOA waveguide from the front facet to the back facet; and emit, from the back facet, an amplified free-space beam that includes the amplified received light. The laser system further includes a mounting platform, where one or more of the seed laser diode, the seed-laser focusing lens, and the SOA are mechanically attached to the mounting platform.

Disclosed is a laser device including: a laser generator configured to generate a laser beam; a first amplifier configured to amplify energy of the laser beam; and a first laser beam width adjuster comprising an aperture disposed between the laser generator and the first amplifier to limit a width of the laser beam. The aperture includes: a light transmissive portion formed to be smaller than the width of the laser beam so as to allow a central part of the laser beam to pass through; a light shielding portion formed to encompass the light transmissive portion to block a periphery of the laser beam; and a soft edge portion formed between the light transmissive portion and the light shielding portion, so that a light transmittance of the light transmissive portion gradually decreases to a light transmittance of the light shielding portion.

A laser light-source apparatus includes a control unit configured to perform control in such a manner that a seed light source is driven in a pulse oscillation mode of oscillating pulse light based on gain switching in an output permitted state where output of pulse light from the apparatus is permitted, and is driven in a continuous oscillation mode of oscillating continuous light in an output stopped state in which the output of the pulse light from the apparatus is stopped, with power of excitation light for a solid state amplifier maintained, and adjusts power of laser light input to the solid state amplifier from the seed light source in the continuous oscillation mode in such a manner that the solid state amplifier outputs light with substantially same average power in the output stopped state and in the output permitted state.

Techniques for controlling an optical system include accessing a measured value of a property of a particular pulse of a pulsed light beam emitted from the optical system, the property being related to an amount of coherence of the light beam; comparing the measured value of the property of the light beam to a target value of the property; determining whether to generate a control signal based on the comparison; and if a control signal is generated based on the comparison, adjusting the amount of coherence in the light beam by modifying an aspect of the optical system based on the control signal to reduce an amount of coherence of a pulse that is subsequent to the particular pulse.

A laser light-source apparatus includes: a fiber amplifier and a solid-state amplifier to amplify pulse light output from a seed light source serving as a first light source; a nonlinear optical element to perform wavelength conversion on the pulse light output from the solid-state amplifier; an optical switching element to permit or stop propagation of the pulse light from the fiber amplifier to the solid-state amplifier; a second light source disposed on an upstream side of the solid-state amplifier and is configured to output laser light able to be combined with the pulse light output from the seed light source; and a control unit to control the optical switching element in such a manner that the propagation of light is stopped and to perform control in such a manner that the second light source oscillates, at least in an output period of the pulse light from the seed light source.

A laser system includes a laser device configured to output pulse laser light, and a first optical pulse stretcher including a delay optical path for stretching a pulse width of the pulse laser light. The first optical pulse stretcher is configured to change a beam waist position of circulation light that circulates through the delay optical path and is output therefrom, in an optical path axis direction according to a circulation count. When the circulation light is condensed by an ideal lens, a light condensing position of the circulation light is changed in the optical path axis direction according to the circulation count.

A laser apparatus includes an oscillator that outputs laser light, an amplifier, a front optical system and a rear optical system that are disposed at positions where the front and rear optical systems face each other with a chamber sandwiched therebetween and constitute a ring resonator having a first optical path and a second optical path, and first plane parallel substrates disposed on the first optical path or the second optical path. The first optical path is an optical path along which the front optical system outputs the laser light. The second optical path is an optical path along which the rear optical system outputs the laser light. The first plane parallel substrates translate the first optical path and the second optical path, respectively, in the directions in which the first and second optical paths approach each other on the side facing the chamber.

Laser-apparatus includes a fiber-MOPA arranged to deliver amplified seed optical pulses having a wavelength of about 1043 nanometers to a multi-pass ytterbium-doped yttrium aluminum garnet solid-state optical amplifier for further amplification.