46W腔内光参量振荡高重复频率2μm激光器

Intracavity Optical Parametric Oscillator High-Repetition-Rate 2μm Laser with 46W Output Power

报道了采用1064 nm激光抽运KTP晶体内腔光参量振荡(OPO)技术实现高重复频率、高效率2μm激光输出的实验结果。理论计算了KTP OPO双谐振抽运阈值,提出了内腔KTP OPO设计思路。激光器采用两块相同的KTP晶体光轴相向放置以补偿走离效应,KTP晶体按φ=0°,θ=53°切割以获得近简并波长2.128μm激光输出。在808 nm激光二极管抽运功率为470 W,声光Q开关工作频率为7.5 kHz的条件下,获得平均功率46.5 W,波长2.128μm激光输出,光-光转换效率为9.89%,斜率效率为14.5%,光束质量M2<2.8。

The experimental results of high-repetition rate and high-efficiency 2 um laser is demonstrated on intracavity optical parametric oscillator （OPO） in KTP pumped by 1064 nm laser. The pumping threshold of KTP doubly resonant OPO is calculated, and the design method of intracavity KTP OPO is proposed. Walk-off compensation is realized by a pair of identical KTP crystals. When cut at φ=0°,θ=53° , a KTP OPO could get output at near degeneration wavelength of 2. 128um. The average output power of 46.5 W at 2. 128 um is obtained under the condition of 470 W laser diode pump power at 808 nm and the acoustic-optical Q switching repetition rate of 7.5 kHz. The optical optical efficiency is 9.89% , the slope efficiency is 14.5% and the M^2 of the output beam is less than 2.8.