基于大芯径晶体波导的半导体可饱和吸收镜锁模激光器

Semiconductor Saturable Absorption Mirror Mode-Locked Laser Based on Large Core Size Crystal Waveguide

大芯径晶体波导可吸收更高功率的泵浦光,能够实现更高的输出功率,同时在锁模运行时芯层中的峰值功率密度相对较低,而且减少了非线性效应的积累。基于此,构建了一种基于Yb:YAG大芯径晶体方波导的被动锁模皮秒激光器。实验中,首先使用高反镜替代半导体可饱和吸收镜(SESAM),在较高的泵浦功率下调节晶体波导的位置和角度以实现泵浦光与波导芯层的匹配;然后,仔细调节球面反射镜的角度,使信号光耦合进波导芯层中以尽量减小腔内的损耗。所设计的激光器采用折叠腔结构,在腔内没有色散补偿器件的情况下,实现了平均功率为10.2 W、脉冲宽度为65 ps、重复频率为30.15 MHz、单脉冲能量为0.34μJ的激光输出。

Large core diameter crystal waveguides can absorb higher power pump light and achieve higher output power.At the same time,the peak power density in the core layer is relatively low during mode-locking operation,and the accumulation of nonlinear effects is reduced.Based on this,a passively mode-locked picosecond laser based on Yb:YAG large core diameter crystal square waveguide is constructed.In the experiment,firstly,the high mirror is used instead of the semiconductor saturable absorption mirror(SESAM),and the position and angle of the crystal waveguide are adjusted to match the pump light with the waveguide core layer under higher pump power.Then,the angle of the spherical mirror is carefully adjusted to couple the signal light into the waveguide core layer to minimize the loss in the cavity.The designed laser adopts a folded cavity structure,and achieves an average power of 10.2 W,pulse width of 65 ps,repetition rate of 30.15 MHz,and single pulse energy of 0.34μJ without dispersion compensation device.