There are provided: a planar waveguide in which claddings (2) and (3) each having a smaller refractive index than a laser medium for absorbing pump light (5) are bonded to an upper surface (1a) and a lower surface (1b) of a core (1) which is formed from the laser medium; pump light generation sources (4a) and (4b) for emitting pump light (5) to side surfaces (1c) and (1d) of the core (1); and laser light high reflection films (6a) and (6b) formed on side surfaces (1e) and (1f) of the core (1). Each of side surfaces (2e) and (2f) of the cladding (2) corresponding to the side surfaces (1e) and (1f) of the core (1) has a ridge structure (20) in which a part thereof is recessed.

Provided herein are systems and methods of manufacture and operation for a compact laser to achieve high-intensity output pulses. These compact laser resonators and methods rely upon separate and distinct functions of the laser resonator to be operated in balance such that the functions, while deleterious when separate are supportive of laser generation and growth when combined within a small volume laser resonator as described herein. The combined elements of the described laser resonator include a delicate balance that allows the laser to operate between plane-parallel operation and unstable operation. This operation mode further allows distinct methods of construction and operation that allow the compact laser to be reliably assembled and tested during assembly. Therefore, despite requiring a delicate balance of disparate elements, the described laser resonator results in a compact robust laser.

A laser system is described, the laser system comprising: an optical cavity defined by at least first and second at least partially reflecting elements; and a gain system. The gain system comprising at least first and second gain media located within the optical cavity. The first and second gain media are configured to generate optical radiation of at least first and second wavelength ranges in response to pumping energy.

A multipass laser amplifier includes a mirror, a mirror device, a gain crystal, and refractive or diffractive beam-steering element. The gain crystal is positioned on a longitudinal axis of the multipass laser amplifier between the mirror and the mirror device. The beam-steering element is positioned on the longitudinal axis between the gain crystal and the mirror device. The beam-steering element has no optical power and deflects a laser beam, by refraction or diffraction, for each of multiple passes of the laser beam between the first mirror and the mirror device, such that each pass goes through the gain crystal for amplification of the laser beam and goes through a different respective off-axis portion of the beam-steering element. The no optical power of the beam-steering element enables maintaining a large beam size in the gain crystal, thereby facilitating amplification to high average power.

There are provided: a planar waveguide in which claddings (2) and (3) each having a smaller refractive index than a laser medium for absorbing pump light (5) are bonded to an upper surface (1a) and a lower surface (1b) of a core (1) which is formed from the laser medium; pump light generation sources (4a) and (4b) for emitting pump light (5) to side surfaces (1c) and (1d) of the core (1); and laser light high reflection films (6a) and (6b) formed on side surfaces (1e) and (1f) of the core (1). Each of side surfaces (2e) and (2f) of the cladding (2) corresponding to the side surfaces (1e) and (1f) of the core (1) has a ridge structure (20) in which a part thereof is recessed.

A laser system having a multi-pass amplifier system which includes at least one seed source configured to output at least one seed signal having a seed signal wavelength, at least one pump source configured to output at least one pump signal, at least one multi-pass amplifier system in communication with the seed source and having at least one gain media, a first mirror, and at least a second mirror therein, the gain media device positioned between the first mirror and second mirror and configured to output at least one amplifier output signal having an output wavelength range, the first mirror and second mirror may be configured to reflect the amplifier output signal within the output wavelength range, and at least one optical system may be in communication with the amplifier system and configured to receive the amplifier output signal and output an output signal within the output wavelength range.

An apparatus for generating and amplifying laser beams at approximately 1 micrometer wavelength is disclosed. The apparatus includes an ytterbium-doped gain-crystal pumped by an ytterbium fiber-laser. The fiber-laser enables a pump wavelength to be selected that minimizes heating of the gain-crystal. The apparatus can be configured for generating and amplifying ultra-fast pulses, utilizing the gain-bandwidth of ytterbium-doped gain-crystals.

The present invention relates an apparatus and method for measuring range-resolved atmospheric sodium temperature profiles using a space-based Lidar instrument, including a diode-pumped Q-switched self-Raman c-cut Nd:YVO.sub.4 laser with intra-cavity frequency doubling that could produce multi-watt 589 nm wavelength output. The c-cut Nd:YVO.sub.4 laser has a fundamental wavelength that is tunable from 1063-1067 nm. A continuous wave narrow linewidth diode laser is used as an injection seeder to provide single-frequency grating tunable output around 1066 nm. The injection-seeded self-Raman shifted Nd:VO.sub.4 laser is tuned across the sodium vapor D.sub.2 line at 589 nm. In one embodiment, a space-qualified frequency-doubled 9 Watt at 532 nm wavelength Nd:YVO.sub.4 laser, is utilized with a tandem interference filter temperature-stabilized fused-silica-etalon receiver and high-bandwidth photon-counting detectors.

A multipass laser amplifier includes a mirror, a mirror device, a gain crystal, and refractive or diffractive beam-steering element. The gain crystal is positioned on a longitudinal axis of the multipass laser amplifier between the mirror and the mirror device. The beam-steering element is positioned on the longitudinal axis between the gain crystal and the mirror device. The beam-steering element has no optical power and deflects a laser beam, by refraction or diffraction, for each of multiple passes of the laser beam between the first mirror and the mirror device, such that each pass goes through the gain crystal for amplification of the laser beam and goes through a different respective off-axis portion of the beam-steering element. The no optical power of the beam-steering element enables maintaining a large beam size in the gain crystal, thereby facilitating amplification to high average power.

A device includes a first sensor configured to generate a first output signal corresponding to an energy of a portion of a forward beam transmitted by a mirror of a laser resonator system. The device further includes a second sensor configured to generate a second output signal corresponding to an energy of a portion of a return beam transmitted by the mirror. A ratio of the energy of the portion of the forward beam and the energy of the portion of the return beam corresponds to a measurement of a feedback ratio of the laser resonator system.