Low Threshold and Highly Efficient All Fiber Brillouin Laser

Using a simple ring cavity experimental setup, a low threshold and highly efficient all fiber Brillouin laser has been demonstrated. Three fibers with different characteristics were tested as the Brillouin gain media. A Non-Zero Dispersion-Shifted Fiber (NZDSF) of 25 km, a Highly Non-linear Fiber (HNLF) of 2 km and a 15 km Dispersion Compensating Fiber (DCF). A laser with bandwidth of 1kHz at a central wavelength of 1565 nm and 14 mW maximum optical power was used as a pump source. Spectral analysis was done using a very high-resolution Optical Spectrum Analyzer (OSA) of 1.12 pm resolution. Even using reasonably low pump powers, laser efficiencies as high as 49.43% were obtained. Additionally, contrarily to most Brillouin fiber lasers, very low thresholds with values around 1.15 mW were experimentally demonstrated.