In one embodiment, a laser system includes a seed laser diode configured to produce a free-space seed-laser beam. The laser system also includes a pump laser diode configured to produce a free-space pump-laser beam. The laser system further includes an optical-beam combiner configured to combine the seed-laser and pump-laser beams into a combined free-space beam and a focusing lens configured to focus the combined beam. The laser system also includes an optical gain fiber that includes an input end configured to receive the focused beam. The laser system also includes a mounting platform, where one or more of the optical-beam combiner, the focusing lens, and the input end of the gain fiber are mechanically attached to the platform.

In one embodiment, an optical amplifier includes a first pump laser diode and a second pump laser diode. The first pump laser diode is configured to produce pump light that includes a first amount of optical power at a first wavelength, and the second pump laser diode is configured to produce pump light that includes a second amount of optical power at a second wavelength different from the first wavelength. The optical amplifier also includes an optical gain fiber configured to receive the pump light from the first and second pump laser diodes and provide optical gain for an optical signal propagating through the optical gain fiber. The optical amplifier further includes a controller configured to adjust the first amount of optical power produced by the first pump laser diode and the second amount of optical power produced by the second pump laser diode.

A laser system includes a first laser source with a laser resonator for generating a first pulsed laser beam. The resonator has a back mirror, an outcoupling mirror and an active lasing medium in between. The system includes a second laser source for generating a second pulsed laser beam and an optical block. The optical block includes a coupling polarizer and a first polarization rotator. The optical block is movable back and forth between an active position and a passive position. In its active position the optical block is located between the outcoupling mirror and the active lasing medium such that the coupling polarizer couples the second beam into the laser resonator of the first laser source while the first rotator is positioned between the outcoupling mirror and the coupling polarizer. In the active position of the optical block a second polarization rotator is between it and the back mirror.

Method for producing ultraintense laser pulses in which Stimulated Raman Back-Scattering (SRBS) amplifies and compresses a seed pulse, as well as an inventive compact plasma device which may implement the method. SRBS may be achieved by counter-propagating the seed pulse and a pump pulse through a few millimeter-long plasma having a plasma frequency equal to the difference between the pump and the seed pulse frequencies. Dichroic mirrors may be arranged to provide two amplifying and compression passes through the plasma, allowing greater seed pulse amplification by mitigating Landau damping within the plasma that would occur in a single pass of a plasma of double the length. Alternate examples provide for 2n number of amplification and compression passes by providing n short plasma columns, where n2, and additional, appropriately arranged dichroic mirrors. The compact size of the device, and the ultraintense, ultrashort pulses it emits, suit the device to dermatological applications.

A laser system includes a laser source operable to provide a laser beam; a laser amplifier having an input port and an output port and operable to amplify the laser beam, the laser beam travelling along a main beam path through the laser amplifier from the input port to the output port; and a residual gain monitor operable to provide a probe laser beam, the probe laser beam travelling along a probe beam path through the laser amplifier from the output port to the input port, wherein the residual gain monitor calculates a residual gain of the laser amplifier according to the probe laser beam.

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.

A solid-state laser system may include: a solid-state laser unit configured to output first pulsed laser light with a first wavelength and second pulsed laser light with a second wavelength; a first solid-state amplifier configured to receive the first pulsed laser light, and output third pulsed laser light with the first wavelength; a wavelength converter configured to receive the third pulsed laser light, and output harmonic light with a third wavelength; a second solid-state amplifier configured to receive the second pulsed laser light, and output fourth pulsed laser light with the second wavelength; a Raman laser unit configured to receive the fourth pulsed laser light, and output Stokes light with a fourth wavelength; and a wavelength conversion system configured to receive the harmonic light and the Stokes light, and output fifth pulsed laser light with a fifth wavelength converted in wavelength from the third wavelength and the fourth wavelength.

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.

Both of multi-mode laser beam 8A and excitation beam 34A for amplification are imputed to an amplification gain medium 62 in a relationship in which their optical axes match each other and an effective beam diameter of the excitation beam for amplification is smaller than an effective beam diameter of the multi-mode laser beam. As a result, laser beam of a part of modes progressing in a radiation range of the excitation beam 34A for amplification is selectively amplified. Laser beam 40A subjected to mode cleaning is thereby outputted.

A solid-state laser system may include: a solid-state laser unit configured to output first pulsed laser light with a first wavelength and second pulsed laser light with a second wavelength; a first solid-state amplifier configured to receive the first pulsed laser light, and output third pulsed laser light with the first wavelength; a wavelength converter configured to receive the third pulsed laser light, and output harmonic light with a third wavelength; a second solid-state amplifier configured to receive the second pulsed laser light, and output fourth pulsed laser light with the second wavelength; a Raman laser unit configured to receive the fourth pulsed laser light, and output Stokes light with a fourth wavelength; and a wavelength conversion system configured to receive the harmonic light and the Stokes light, and output fifth pulsed laser light with a fifth wavelength converted in wavelength from the third wavelength and the fourth wavelength.