High-repetition-rate MHz acoustooptic Q-switched fiber laser

A simple actively Q-switched double-clad fiber laser combining an amplifying cavity is reported by using a dynamic acoustooptic Q-switching as a beam splitter. Sub-100-ns. pulses independence of the repetition rate of acoustooptic modulator are almost changeless with repetition rate varied from 50 kHz to 1.5 MHz. With 4.5-W absorbed power, 9.4-W peak-power pulses at 1.5-MHz repetition rate with 75-ns pulse duration are generated.

A planar waveguide Nd : YAG laser using active Q-switching of a hybrid unstable resonator

A planar waveguide laser operating in a negative branch unstable resonator is Q-switched by an acoustooptic mod latorin anew configuration, providing effective, high-speed switching. The laser using a 200-mu m Nd:YAG core, face pumped by 10 laser diode bars, has produced 100-W output in a good beam quality at 100-kHz pulse rate, and 4.5 mJ at lower frequency with 15-ns pulse duration.

新型声光通信激光多普勒信号的鉴频电路

根据激光多普勒测振技术进行声光通信的工作原理,设计一种新型、小型激光多普勒测振信号鉴频电路。该电路根据外差探测原理,本地振荡器输出信号与探测信号混频得到一路信号,经90°移相后的本地振荡器输出信号再与探测信号混频得到另一路信号,利用这两路信号得到了多普勒频移量和声源振动的频率。利用扬声器激发的水面模拟振源进行实验,表明该电路可有效测量的振动频率范围为300 Hz~10 kHz,证明可用于水下光声通信。