高效率内腔式2μm简并光学参量振荡器

High-efficiency intracavity 2 μm degenerate optical parametric oscillator

报道了一种高效率的2μm光学参量振荡器.利用1.064μm声光调Q Nd:YVO4激光器抽运基于氧化镁掺杂周期性极化铌酸锂的内腔式光学参量振荡器,在简并状态实现了稳定高效的2μm激光输出.当808 nm激光二极管抽运功率为20 W,Q开关工作频率为15 k Hz时,产生了平均功率为3.5 W、脉冲宽度为1.4 ns的2μm激光,光-光转换效率为17.5%,斜效率为25%.据我们所知,该转换效率在2μm波段内腔式光学参量振荡器中是最高的.

A high-efficiency 2 9m optical parametric oscillator based on MgO-doped periodically poled LiNbO3 intracavity pumped by a 1.064 μm Q-switched Nd：YVO4 laser is reported. With the intense fluence inside the laser cavity, a maximum 2 μm average power of 3.5 W is obtained at 15 kHz repetition rate in a degenerate state. A maximum optical-to-optical conversion efficiency of 17.5% with a slope efficiency of 25% is achieved when the laser diode power is 20 W. To the best of our knowledge, the efficiency is the highest ever achieved from an intracavity degenerate optical parametric oscillator in 2 μm region. The pulse duration of 2 μm is 1.4 ns, which is much shorter than that of 1.064 pro. A bandwidth of 30 nm is obtained at a degenerate wavelength of 2128 nm. The M2 values for the 2 μm beam are 3.47 and 3.54 in the horizontal and vertical directions, respectively. The standard deviation of the power fluctuation is -2% at the maximum power in half an hour.