High repetition-rate and short pulse-width 1064nm laser in a composite crystal device

Abstract

Compared with lamp pumped solid state laser, laser-diode pumped all-solid-state laser (DPSL) has the characteristic of high efficiency, long life and reliable under the condition of high repetition rate. Therefore, A high repetition rate DPSL has a broad application prospect in the laser detection, laser communication and optoelectronic countermeasure and other fields. Laser-diode (LD) pumped acousto-optic(AO) Q-switch all-solid-state has attractive features, such as compact structure, reliable operation, high repetition rate and short pulse width. Laser crystal is the core component of the laser. Usually composite crystal thermal lens focal length is three times more than traditional crystal, so it can avoid the serious heating effect of the operation material bumping by the traditional method. In this paper, we present a high repetition rate acousto-optic Q-switched Nd:YVO 4 laser pumped by 880nm laser diode. By using the 0.25% doping concentration Nd:YVO 4 single end composite crystal size of 3*3*(4+16) mm 3 , with the 50 W LD pumped power, in order to calculate the laser crystal absorption efficiency of pump light, so that more accurate calculation of light conversion efficiency, first we measured 880 nm pump light absorption, crystal is calculated on the pump light absorption efficiency of 75%; When we put in the cavity mirror to form a flat resonant cavity, we obtained the 1064 nm continuous laser output power of 26 W and 27.1 W, with the output mirror transmittance of 20% and 48%, respectively. 50.7% and 48.7% optical to optical conversion efficiency has been achieved experimentally. When we put in AO Q-switch, with the repetition rate of 50 kHz, 100 kHz and 200 kHz, the 1064 nm laser output power is 21 W, 21.28 W and 20.58 W, and the peak power is 32.9 kW, 17.3 kW, 8.5 kW, respectively. Under the high repetition rate circumstance, the pulse width is limited to 12 ns.

Kilowatt-level 100 kHz nanosecond pulsed laser amplifier via a 205-watt seeding

“…Nanosecond (ns) pulsed laser with high average power and high pulse repetition rate (PRR) above 50 kHz is a potential solution for laser cutting, laser welding, laser cleaning and many other industry processing scenarios, becoming the difficulty and focus of pulsed laser 1 . Due to the influence of thermo-mechanical properties, the output power of lasers with gain mediums such as Nd:YVO 4 and Nd:GdVO 4 , which are commonly used in high PRR Q-switching at 50 kHz and above, is limited, the current achievements are mainly concentrated on the order of tens of watts [2][3][4][5][6][7] . Nd:YAG is a widely used solid-state gain medium with many advantages such as high mechanical strength, high thermal conductivity and great optical properties.…”