Abstract

A micrometer droplet acts as a waveguide for nonlinear waves generated by a tightly focused incident beam nearly tangent to the droplet equator. The whispering-gallery modes confine the stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS) by total internai reflection near the droplet surface. The clockwise- and counterclockwise-circulating SBS and SRS will experience either near-forward or nearbackward gain. The sense of circulation can be readily identified by measuring the nonlinear radiation leaking from the two droplet edges, regardless of the detection angle relative to the input-pump-beam direction. The near-forward SBS is easily discriminated from the input-pump beam by placing the detector at an angle to the pump beam direction, e.g., 90° or 160°. The SBS and the SRS images appear as short arcs on the droplet rim, centered about the equator.

© 1994 Optical Society of America