Esteban-Martin A, Kokabee O, Ebrahim-Zadeh M
ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, Barcelona, Spain.
Opt Lett. 2008 Nov 15;33(22):2650-2. doi: 10.1364/ol.33.002650.
We report efficient generation of tunable femtosecond pulses in the red by internal frequency doubling of an optical parametric oscillator (OPO) based on periodically poled LiNbO3 (PPLN). The OPO, based on a 1-mm-thick PPLN crystal, is synchronously pumped by a femtosecond Ti:sapphire laser at 810 nm, providing signal pulses across 1.33-1.57 microm at a 76 MHz repetition rate. Using a 1-mm-thick crystal of BiB3O6 (BIBO) internal to the OPO cavity, we achieve frequency doubling of signal pulses across 665-785 nm with up to 260 mW of average power for 1.51 W of pump. The high nonlinear gain and phase-matching acceptance in PPLN and BIBO permit convenient tuning across the full range by simple detuning of OPO cavity delay. Intracavity dispersion compensation results in near-transform-limited red pulses with durations down to 140 fs for 185 fs input pump pulses.
我们报道了基于周期性极化铌酸锂（PPLN）的光学参量振荡器（OPO）通过内腔倍频高效产生可调谐的红色飞秒脉冲。该OPO基于一块1毫米厚的PPLN晶体，由一台810纳米的飞秒钛宝石激光器同步泵浦，以76兆赫兹的重复频率产生波长范围在1.33 - 1.57微米的信号脉冲。利用OPO腔内一块1毫米厚的硼酸铋（BiB3O6，BIBO）晶体，对于1.51瓦的泵浦功率，我们实现了波长范围在665 - 785纳米的信号脉冲倍频，平均功率高达260毫瓦。PPLN和BIBO中高的非线性增益和相位匹配容限使得通过简单调节OPO腔延迟就能在整个范围内方便地调谐。腔内色散补偿产生了近变换极限的红色脉冲，对于185飞秒的输入泵浦脉冲，脉冲持续时间可低至140飞秒。
