Coherent combination of micropulse semiconductor amplifiers for water vapor differential absorption lidars

We report on the design of a compact master oscillator power amplifier (MOPA) diode laser architecture at 828 nm suitable for direct-detection LIDARs, specifically applied to water vapor differential absorption LIDARs. Coherent beam combination of two pulsed high-brightness tapered amplifiers (1 μs, 10 kHz), seeded by a DBR laser diode, is demonstrated. The phase dynamics during the pulses have been thoroughly investigated. The main limitation to the CBC efficiency is quantified. The maximum combined pulse energy reaches 10.3 μJ with combining efficiency above 82% ± 5%.