Monolithic high SBS threshold pulsed fiber laser and frequency doubling for LIDAR and remote sensing spectroscopy

We report a monolithic high SBS-threshold pulsed fiber laser in MOPA for longer nanosecond pulses with transformlimited linewidth. By using a single mode polarization-maintaining large core 25 μm highly Er/Yb co-doped phosphate fiber in the power amplifier stage, we have achieved the highest peak power of 1.2 kW at 1530 nm for 105 ns pulses with transform-limited linewidth, and with a corresponding pulse energy of about 0.126 mJ. The achieved high-energy pulses were frequency doubled by using a commercial periodically poled lithium niobate (PPLN) crystal, and the highest SHG peak power of 271 W has been achieved for the SHG pulses at 765 nm.