Controlling the long-term dynamics of Brillouin Fiber Lasers using pump modulation: Bi-stable lasing and Hysteresis

Abstract

The long-term lasing dynamics of Brillouin Fiber Lasers was recently shown to be governed by an intrinsic thermal feedback which stabilizes the lasing frequency at the lower half of the gain line. We show that this feedback can be utilized by means of pump modulation to greatly control this dynamics. Specifically, we demonstrate experimentally a bi-stable fiber laser where switching between lasing modes is possible by either controlling the cavity length or pump power. An inherent hysteretic response ensures the long-term stability of the laser in each mode. Excellent agreement is found between the experimental results and a master-equation based theoretical model.