An acousto-optic deflector includes an optical element having a surface with one or more steps formed thereon; a conductive layer formed on the surface with the steps; one or more crystals secured to each step; and electrodes positioned on each surface of each crystal.

An acousto-optic deflector includes an optical element having a surface with one or more steps formed thereon; a conductive layer formed on the surface with the steps; one or more crystals secured to each step; and electrodes positioned on each surface of each crystal.

The present disclosure relates a laser arrangement (1) and a method of the laser arrangement, arranged to output energy in the form of laser emission, for emitting controlled Q-switched laser emission. The laser arrangement comprises a gain medium (2) arranged to be excited when pumped, an optical resonator (3), an active Q-switch (4) arranged in the optical resonator, said active Q-switch (4) being controllable between at least a high loss state and a low loss state, and being arranged to introduce loss in the optical resonator to prevent lasing in the high loss state and to affect lasing minimally in the low loss state, a photo detector (5) arranged to detect the presence of a free running pulse (1) generated by the optical resonator and which occurs when a lasing threshold is reached and a processing circuitry (6) arranged to control (S4) of the state of the active Q-switch based on the detection of the free running pulse.

The present disclosure relates a laser arrangement (1) and a method of the laser arrangement, arranged to output energy in the form of laser emission, for emitting controlled Q-switched laser emission. The laser arrangement comprises a gain medium (2) arranged to be excited when pumped, an optical resonator (3), an active Q-switch (4) arranged in the optical resonator, said active Q-switch (4) being controllable between at least a high loss state and a low loss state, and being arranged to introduce loss in the optical resonator to prevent lasing in the high loss state and to affect lasing minimally in the low loss state, a photo detector (5) arranged to detect the presence of a free running pulse (1) generated by the optical resonator and which occurs when a lasing threshold is reached and a processing circuitry (6) arranged to control (S4) of the state of the active Q-switch based on the detection of the free running pulse.

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.

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.

Aspects of the present disclosure are directed to methods and apparatuses for generating laser light. As may be implemented in accordance with one or more embodiments, laser light is generated at a laser light source and is modulated in response to a frequency modulation signal, to generate a plurality of different wavelengths of laser light. The frequency modulation signal is generated, for each particular one of the wavelengths of laser light, at a respective seeding frequency corresponding to the particular one of the wavelengths in which the seeding frequency is different for each of the different wavelengths. Such an approach may, for example, involve generating the frequency modulation signal with a frequency generator circuit and using the frequency modulation signal to control an electro-optical modulator for modulating the wavelength of the laser light.

Aspects of the present disclosure are directed to methods and apparatuses for generating laser light. As may be implemented in accordance with one or more embodiments, laser light is generated at a laser light source and is modulated in response to a frequency modulation signal, to generate a plurality of different wavelengths of laser light. The frequency modulation signal is generated, for each particular one of the wavelengths of laser light, at a respective seeding frequency corresponding to the particular one of the wavelengths in which the seeding frequency is different for each of the different wavelengths. Such an approach may, for example, involve generating the frequency modulation signal with a frequency generator circuit and using the frequency modulation signal to control an electro-optical modulator for modulating the wavelength of the laser light.

An optical system for producing pulsed laser output includes a laser cavity containing an active medium for generating laser radiation; and an acousto-optic modulator (AOM) positioned in the laser cavity for modulating the laser radiation acting as a Q-switch.

An optical system for producing pulsed laser output includes a laser cavity containing an active medium for generating laser radiation; and an acousto-optic modulator (AOM) positioned in the laser cavity for modulating the laser radiation acting as a Q-switch.