1550nm全光纤单频脉冲光纤激光器

1550nm all-fiber single-frequency pulsed fiber laser

设计并实现了一种基于人眼安全波段的1550 nm全光纤化结构单频脉冲光纤激光器。激光器采用外腔稳频技术的单频半导体激光器作为种子源,其线宽1. 8 kHz,功率20 m W。通过预放大器和声光调制器获得单频脉冲激光,并运用两级光纤放大器实现了线宽1. 9 kHz、平均功率521 m W、脉冲宽度200 ns、重复频率10 k Hz的单频脉冲光纤激光输出。输出脉冲峰值功率达260 W。输出端采用了双包层单模光纤,保证了输出激光的光束质量。整个激光器通过对种子光级联放大,结合放大器的增益控制,成功抑制了受激布里渊散射(Stimulated Brillouin Scattering,SBS)效应,消除了放大过程中噪声对线宽的影响,获得了线宽稳定的单频脉冲激光。

A 1550nm all-fiber single-frequency pulsed fiber laser based on eye-safely spectral range was achieved in this paper. The laser adopts the single-frequency semiconductor laser with external cavity frequency stabilization technology as the seed source,whose line width is 1.8 kHz and power is 20 mW. First,the seed power was amplified by pre-amplifier, then pulse laser was obtained by acoustic optical modulator. Later two power amplifier was applied, and an line width 1.9 kHz single-frequency pulsed fiber laser was realized with average power of 521 mW, pulse width of 200 ns and repetition rate of 10 kHz. The laser pulse peak power was 260 W. Because an double-clad single mode fiber was applied in output end, the laser beam quality was keeped well. The whole fiber laser system employed the structure of cascading amplifying, and applied gain control technology in fiber amplifer. Thus the Stinmlated Brillouin Scattering effect was suppression successfully, and the ilffluenee of noise to line width was eliminated in the amplifying process. Accordingly, an single-frequency pulse laser with stable line width was obtained.