Stabilized single-frequency stimulated Brillouin fiber ring laser.

The detailed behavior of the cw stimulated Brillouin fiber laser has been studied by using a narrow-linewidth cw pump argon laser at 5145 A and an 83-m fiber ring cavity. By stabilizing the fiber cavity, we achieved stable single-frequency Brillouin-laser output with a linewidth determined primarily by the 100-kHz modulation used in the feedback system. Lasing threshold for the 4.5-microm-core fiber used was observed at a pump power of 77 mW, and the maximum Brillouin output was 13 mW for a pump of 320 mW. The Brillouin gain medium was shown to exhibit homogeneouslike behavior.