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.