<title>Time-dependent modeling of the MFA-MOPA</title>

Abstract

Semiconductor lasers present enormous potential for free-space laser communications. Recently, a new class of devices based on a master oscillator power amplifier configuration has emerged as the leading contender. The paper illustrates the monolithically integrated flared amplifier (MFA-MOPA) device. It incorporates an index-guided, single-lateral-mode- distributed Bragg reflector (DBR) master oscillator section that diffracts a relatively low- power, narrow spectral bandwidth signal into a tapered amplifier section. The tapered amplifier section then amplifies the output to a one-watt or greater level while the divergence precludes the formation of filaments, maintaining good beam quality during the amplification process. The final output facet of the amplifier section is anti-reflection coated so that feedback into the DBR master oscillator is minimized, while outcoupling the amplified power.