DISTRIBUTED FEEDBACK (DFB) BRILLOUIN FIBER LASERS

摘要

A Brillouin fiber laser uses a distributed feedback (DFB) fiber Bragg grating with a discrete π-phase shift, which is offset from the physical center of the grating as a resonator. Lasing is achieved by using the SBS gain in the DFB from narrow-linewidth laser pump radiation with an optical frequency that is higher than the central pass band of the grating by an amount nominally equal to the Stokes's frequency shift, ν_B. The lasing occurs at a wavelength that corresponds to the first Stokes wave. The Brillouin DFB fiber laser has a low threshold, does not require any fiber optic couplers, does not require rare-earth doping, enables connection of many DFB lasers in series, pumping using a multi-wavelength or wavelength tunable laser sources, and the laser output can be delivered along the direction of the pump propagation or in the reverse direction.