High-Energy, Short-Pulse Fiber Injection Lasers at Lawrence Livermore National Laboratory

A short-pulse fiber injection laser for the advanced radiographic capability on the National Ignition Facility has been developed at Lawrence Livermore National Laboratory. This system produces 100 ¿J pulses with 5 nm of bandwidth centered at 1053 nm. The pulses are stretched to 2.5 ns, and have been recompressed to subpicoseconds pulsewidths. A key feature of the system is that the prepulse power contrast ratio exceeds 80 dB. The system can also precisely adjust the final recompressed pulsewidth and timing, and has been designed for reliable, hands-free operation. The key challenges in constructing this system were control of the SNR, dispersion management, and managing the impact of self-phase modulation on the chirped pulse.