A FREQUENCY-UPSHIFTING BRILLOUIN ENHANCED 4-WAVE-MIXING SCHEME USING AN IODINE LASER AS A PUMP SOURCE

Abstract

The characteristics of temporal modulation and frequency recovery in frequency-upshifting Brillouin-enhanced four-wave mixing (BEFWM) using CS2 as a nonlinear medium were investigated experimentally for an iodine laser. BEFWM interaction in a stimulated Brillouin scattering (SBS) generator-amplifier scheme was tested, first, and compared with a new BEFWM scheme in which the amplifier cell is placed out of the beam path of the SBS signal originating from the generator cell, allowing a more efficient and more strongly compressed pulse. The output signal from BEFWM recovers the original laser frequency by frequency-upshifting a Stokes-shifted probe. A pulse compression from 50 ns to 3 ns between the incident laser pulse and the output signal and a power conversion efficiency of 30% with respect to the Stokes-shifted pump were obtained through BEFWM.