Abstract

A comprehensive experimental investigation of phase locking between two beams by stimulated Briliouin scattering (SBS) was conducted. The objective was to determine the conditions in which good coupling and aberration correction could be achieved and identify the underlying physics issues governing this process. A spatially filtered Molectron Nd:YAG laser, doubled to 532 nm, was used as the pump source. Tests were conducted over a wide range of parameters including bandwidth (100 MHz-15 GHz), f/No. near-field and far-field separation between beams, power ratio between beams, and optical path difference relative to the laser coherence length. Experiments were conducted with and without applied aberrations. Diagnostics included Mach-Zehnder interferometers, CCD cameras (far-field), and ghost beam joulemeter measurements. Ranges of near-field and far-field separation over which good phase-locking and piston-error correction have been determined. It was found that alignment tolerances were relaxed for decreased near-field separation, and the locking range was increased for Increased pump beam aberration.

© 1988 Optical Society of America