The present application discloses a nonlinear optical crystal material, preparation method and application of the nonlinear optical crystal material. The nonlinear optical crystal material has an excellent infrared nonlinear optical performance, whose frequency-doubling intensity can reach 9.3 times of AgGaS.sub.2 with the same particle size, and it meets type-I phase matching; and its laser damage threshold can reach 7.5 times of AgGaS.sub.2 with the same particle size. The nonlinear optical crystal material has important application value in the frequency-converters which can be used for frequency doubling, sum frequency, difference frequency, optical parametric oscillation of laser in mid and far infrared waveband, and the like.

A laser comprises a first end mirror and a second end mirror defining an optical cavity therebetween, a first gain medium and a second gain medium positioned in the optical cavity, at least one radiation source configured to provide pump radiation to the first and second gain media, wherein the pump radiation comprises a first pump beam directed to be incident on the first gain medium and a second pump beam directed to be incident on the second gain medium so as to stimulate emission of radiation from the first and second gain media thereby establishing a laser beam in the optical cavity and a control apparatus operable to adjust a property of at least one of the first and second pump beams and thereby control a thermal lens of at least one of the first and second gain media so as to substantially remove an instability zone from the power curve of the laser.

A laser that emits light at all available frequencies distributed throughout the spectral bandwidth or emission bandwidth of the laser in a single pulse or pulse train is disclosed. The laser is pumped or seeded with photons having frequencies distributed throughout the superunitary gain bandwidth of the gain medium. The source of photons is a frequency modulated photon source, and the frequency modulation is controlled to occur in one or more cycles timed to occur within a time scale for pulsing the laser.

A solid-state laser active medium comprising an optical gain material; a heat sink, wherein the heat sink is transparent, in particular over a wavelength range of 200 nm to 4000 nm, preferably with an absorption coefficient of <1 cm.sup.−1; the heat sink having a high thermal conductivity, in particular ≧149 W/(m*K); wherein the optical gain material and the heat sink exhibit a root-mean square, RMS, surface roughness of <1 nm; wherein the optical gain material is attached to the transparent heat sink by direct bonding.

Devices and associated methods for measuring orientation using an optical gyroscope are disclosed. One example optical gyroscope includes a spherical component configured to allow propagation of light in one or more confined modes inside the spherical component. The spherical component includes a gain medium for enhancing a sustained confinement of light within the spherical component. The optical gyroscope also includes one or more detectors positioned outside of the spherical component to detect at least one characteristic of the light, or a change thereto, in response to a rotation of the optical gyroscope.

A radially polarized optical parametric amplifier insensitive to polarization is provided by the present invention, which comprises a laser module and a nonlinear crystal satisfying the type-II phase matching or the type-II quasi-phase matching condition, wherein the laser module is configured to generate two laser beams, namely the pump light and the signal light with an arbitrary polarization state, the wavelengths of the pump light and the signal light are degenerate or nearly degenerate; and the nonlinear crystal is provided in the emergent beamline of the laser module to perform optical parametric amplification of the signal light by using the pump light.

Various embodiments provide a high-efficiency and directional non-resonant laser using a scattering cavity and a method of manufacturing the same. According to various embodiments, the non-resonant laser may include a gain medium unit in which a scattering cavity and an entrance communicating with the scattering cavity are provided, and a pumping and supply unit configured to supply pumping light to an inside of the scattering cavity. The gain medium unit may be implemented to be excited by the pumping light on the inside of the scattering cavity and to output emission light through the entrance. According to various embodiments, the gain medium unit may weaken the pumping light while reflecting the pumping light on the inside of the scattering cavity, and may amplify the emission light while reflecting the emission light on the inside of the scattering cavity.

An optical system element includes a first enclosure designed for receiving in circulation a functional fluid and at least one inlet and/or outlet window located on the first enclosure and through which a light beam can pass. The inlet and/or outlet window includes two viewports which delimit a spacer cavity adjacent to the first enclosure. The spacer cavity is designed to receive a second fluid with a predetermined optical index and is equipped with a device for adjusting the pressure therein. Degradation of a beam during its passage through the inlet and/or outlet window can be limited by careful selection of the optical index of the second fluid and the pressure in the spacer cavity.

A high average and peak power single transverse mode laser system is operative to output ultrashort single mode (SM) pulses in femtosecond-, picosecond- or nanosecond-pulse duration range at a kW to MW peak power level. The disclosed system deploys master oscillator power amplifier configuration (MOPA) including a SM fiber seed, outputting a pulsed signal beam at or near 1030 nm wavelength, and a Yb crystal booster. The booster is end-pumped by a pump beam output from a SM or low-mode CW fiber laser at a pump wavelength in a 1000-1020 nm wavelength range so that the signal and pump wavelengths are selected to have an ultra-low-quantum defect of less than 3%.

A multi-wavelength laser device equipped with a linear cavity along which a first direction and a second direction opposite to the first direction are defined is disclosed. The apparatus includes, along the first direction, a first optical component, a gain and Raman medium, a sum frequency generation crystal, a first second-harmonic generation crystal and a second optical component. The first optical component allows a pumping light to transmit therethrough and be incident in the first direction. The gain and Raman medium receives the pumping light from the first optical component and generates a first infrared base laser light having a first wavelength and a second infrared base laser light having a second wavelength. The first and second optical components form a laser cavity for oscillation of these two infrared base laser lights. The sum frequency generation crystal receives the first and second infrared base laser lights and generates a first visible laser light having a third wavelength. The first second-harmonic generation crystal receives the first infrared base laser light and generates a second visible laser light having a fourth wavelength. The second optical element allows the first and the second visible laser lights to emit out along the first direction.