Two stage Innoslab amplifier for energy scaling from 100 to >500 mJ for future lidar applications.

An Nd:YAG-MOPA system consisting of a stable oscillator and two subsequent Innoslab-based amplifier stages has been designed and built as a technology demonstrator for future lidar applications. Overall, the authors demonstrate that it generates more than 500 mJ of pulse energy at a 1064 nm wavelength and 100 Hz pulse repetition frequency at about 30 ns pulse duration in the single longitudinal mode. Seeded with 75 mJ pulses, the second amplifier stage achieved an optical efficiency (extracted energy to pump energy) of more than 23% while preserving excellent beam quality. To address the 500 mJ regime while retaining the basic system properties, an established Innoslab design was scaled geometrically.