Intracavity changes in the field statistics of Raman fiber lasers.

We present an experiment in which intracavity optical power spectra of a Raman fiber laser are precisely measured both in the forward and in the backward propagation directions near the cavity mirrors. The statistical properties of the intracavity Stokes field are found to be very different before and after reflection on the cavity mirrors. The influence of both the dispersion and the spectral filtering actions of fiber Bragg grating mirrors are discussed.