Experimental investigation of relative intensity noise in Brillouin fiber ring lasers for microwave photonics applications

Intensity noise characteristics of a single-mode Brillouin fiber ring laser are experimentally analyzed from 100 kHz up to 18 GHz. The Stokes wave is shown to be shot-noise limited to -155 dB/Hz for a 1 mA detected photocurrent over the whole spectral range 100 MHz-18 GHz. The pump-to-Stokes noise filtering efficiency is evaluated by artificially increasing the pump intensity noise. It evidences that a shot-noise-limited Brillouin laser could be realized by using a narrow-linewidth semiconductor laser pump, for stringent microwave photonics applications.