Observation of high-contrast, fast intensity noise of a continuous wave Raman fiber laser

We investigate the intensity noise of a continuous-wave Raman fiber laser based on a novel technique where the noise is sampled with a low repetition rate signal in a low walk-off Raman amplifier configuration. With this method, we experimentally demonstrate that continuous-wave Raman fiber lasers exhibit high contrast intensity fluctuations on a timescale of several tens to hundreds of GHz. In fact, the power of the Raman laser fluctuates between nearly zero and a high multiple of the average power. Numerical simulations are used to study the role of pump depletion on the noise transfer process. Our study validates models of pumps used in some recent continuous wave supercontinuum generation simulations. (C) 2009 Optical Society of America