高转换效率单谐振连续波近红外光学参量振荡器

提出了一种高功率及高转换效率的可调谐连续波近红外外腔单谐振光学参量振荡器。为了获得短波段近红外可调谐激光光源，基于准相位匹配晶体的光学参量振荡技术是其中一项有效的技术手段。光学参量振荡器采用连续波532 nm激光器作为泵浦源，掺杂氧化镁的周期性极化化学计量比钽酸锂（MgO:sPPLT）晶体作为准相位匹配晶体，通过在周期调谐的基础上再结合温度调谐的组合调谐方式，在8.3~8.6 μm的4个极化周期内实现了信号光807~879 nm和闲频光1352~1567 nm近红外宽波段的无跳模可调谐激光输出。通过闲频光单谐振设计，当泵浦功率5.4 W时，在8.6 μm周期处，获得了3.1 W的821 nm的近红外信号光输出，实现了57.4%的信号光光-光转换效率。当泵浦功率达到13.6 W时，在8.6 μm周期处，获得了6.8 W的高功率输出。

High-conversion-efficiency continuous-wave near-infrared singly resonant optical parametric oscillator

High-power, high-conversion-efficiency and tunable continuous-wave (CW) near-infrared external-cavity pumped singly resonant optical parametric oscillator (SRO) was proposed. OPO based on a quasi-phase-matched (QPM) nonlinear crystal was a very effective technology to obtain the short-wave near-infrared tunable laser sources. CW laser at 532 nm was used as the fundamental laser source to drive the OPO in the cavity. The QPM crystal was a multi-grating MgO-doped stoichiometric periodically poled LiTaO₃(MgO:sPPLT). The widely tunable SRO output signal wavelength ranging from 807 to 879 nm and idler wavelength ranging from 1352 to 1567 nm were achieved by combination of poling period tuning and temperature tuning with four different periodically poled gratings from 8.3 to 8.6 μm. By means of using single resonant of idler light, the output power of the signal (821 nm) was 3.1 W at a pump power of 5.4 W with the efficiency of 57.4% was achieved. Under an incident pump power of 13.6 W, a maximum signal output power of 6.8 W at 821 nm was obtained with the period of 8.6 μm.