Abstract

We have recently reported a laser amplification technique that allows pulses of up to 1 μs in duration to be efficiently generated from a master oscillator power amplifier (MOPA) geometry.¹ The amplification of the leading edge of the output of a free-running master oscillator gives rise to a quasi-constant output power so that no electro-optical pulse carving, shaping, or electronic feedback is required to produce near-rectangular amplified output pulses. The incorporation of very low threshold SBS phase conjugation using Brillouin-enhanced four- wave mixing provides near-diffraction- limited divergence and the output pulses can be frequency-doubled to 527 nm with >50% total external conversion efficiency.

© 1996 Optical Society of America