Brillouin fiber laser using As38Se62 suspended-core chalcogenide fiber

In this paper, an all-fiber Brillouin laser ring cavity using a 3-m-long suspended-core chalcogenide As 38 Se 62 fiber is reported for the first time to our knowledge. For a nonresonant ring cavity with no servo-locking, a laser threshold power of 37 mW and an efficiency of 26 % were obtained for a fiber having a core diameter of 5 μm. The linewidth of the Brillouin fiber laser and the pump laser were respectively measured to be below 4 kHz, the resolution of our autocorrelator, and 250 kHz, thus showing the linewidth-narrowing nature of the Brillouin laser. This result paves the way to compact Brillouin lasers with low threshold power and good spectral purity. A full experimental Brillouin characterization is also reported. We measured a Brillouin gain spectrum of 14.2 MHz, a Brillouin gain coefficient of 5.6x10 -9 m/W and a Brillouin frequency shift of 7.95 GHz in our fiber.