An Eye-Safe, SBS-Free Coherent Fiber Laser LIDAR Transmitter with Millijoule Energy and High Average Power

We report on an eye-safe, transform-limited, millijoule energy, and high average power fiber laser. The high gain and short length of the NP phosphate-glass fibers enable the SBS-free operation with kW level peak power. The output energy is up to 1.3 mJ, and the average power is up to 23 W at an 18 kHz repetition rate with 600 ns pulses (peak power > 2.1 kW). The PER is approximate to 16 dB and the M-2 of the beam is 1.33 x 1.18. The coherent LIDAR Figure Of Merit (FOM) is 174 mJ*sqrt(Hz), which to our knowledge is the highest reported for a fiber laser. We also report 0.75 mJ energy and >3.7 kW peak power with down to 200 ns pulses and up to 1.21 mJ energy with a 3-5 kHz repetition rate operation of the current system.

Automated summary

In this report, an eye-safe and high average power fiber laser with millijoule energy output is discussed. The optimization of NP phosphate-glass fibers led to SBS-free operation with kW level peak power and high beam quality. The laser achieved a coherent LIDAR Figure Of Merit (FOM) of 174 mJ*sqrt(Hz), the highest reported value for a fiber laser to date.