NONLINEAR-OPTICAL MODULATOR FOR HIGH-POWER FIBER LASERS

We propose a novel nonlinear-optical fiber modulator for high-power (> 1-W) single-mode fiber lasers. The device is based on transferring the amplitude modulation from a low-power signal at the Stokes frequency onto a high-power beam through stimulated Raman scattering. The effici ency and limitations of the Raman modulator when highly Ge-doped fiber is used is considered. An insertion loss of less than 0.4 dB and an e xtinction ratio of 20 dB are predicted for modulation of a 10-W single -mode Nd-doped fiber laser. (C) 1997 Optical Society of America.