非线性晶体对皮秒SESAM被动锁模激光器脉宽的影响

Stretch and compress of LD end pumped all solid state picosecond SESAM passively mode locking lasers

介绍了皮秒激光器脉宽压缩和展宽的的应用需求和传统的实现方法,同时论述了在腔内利用相位失配的倍频晶体进行脉宽的压缩和展宽的原理。实验研究了在半导体泵浦的Nd∶YVO_(4)半导体可饱和吸收体(SESAM)被动锁模激光器腔内,在相位失配的情况下,插入Ⅰ类相位匹配LBO晶体,可以把激光脉冲宽度从8.7 ps压缩到4.8 ps;而腔内插入不同厚度Ⅱ类相位匹配KTP晶体,可以把激光脉宽展宽到12.8 ps、42.8 ps甚至63 ps。并对脉冲宽度的压缩和展宽进行了原理上的论述,扩展了SESAM锁模激光器在激光测距和激光加工以及激光雷达探测等应用中适用范围。

In this paper, the application requirement and traditional method of pulse width compression and broadening of picosecond laser are introduced, and the principle of pulse width compression and broadening using phase mismatched frequency doubling crystal in the cavity is discussed.A class I phase-matched LBO crystal is inserted into the cavity of a passively mode-locked Nd ∶YVO4 semiconductor saturable absorber(SESAM) laser pumped by a semiconductor, the pulse width can be compressed from 8.7 ps to 4.8 ps, and the pulse width can be broadened to 12.8 ps, 42.8 ps or even 63 ps by inserting KTP crystals with different thickness and phase matching.The compression and broadening of pulse width are discussed in principle, and the application range of SESAM mode-locked laser in laser ranging, laser processing and laser radar detection is extended, which has certain reference value in laser ranging, laser processing and lidar detection.