Tunable multiwavelength generation based on Brillouin-erbium comb fiber laser assisted by multiple four-wave mixing processes.

A tunable multiwavelength Brillouin-erbium comb fiber laser with ultra-narrow wavelength spacing and a large wavelength number, employing a 135-m highly nonlinear fiber, has been experimentally demonstrated. The simultaneous presence of Brillouin pump and Stokes lines within the ring cavity initiate higher-order Stokes and anti-Stokes lines via multiple four-wave mixing processes. The experiment demonstrates that this is an effective solution of increasing the number of lasing lines. Up to 150 lasing lines in single-longitudinal-mode operation with a rigid wavelength spacing of 0.075 nm have been achieved at 1480 nm pump powers of 165 mW and Brillouin pump power of 12.0 dBm. The multiwavelength source exhibits a good stability on both the operating wavelengths and the output powers, and a 6-nm tuning range from 1562 nm to 1568 nm is obtained.