Stability investigation of a multi-wavelength fiber linear cavity laser using a highly nonlinear fiber

Abstract

A stable multi-wavelength fiber linear cavity laser based on cascaded four-wave mixing in a highly nonlinear fiber is proposed and experimentally demonstrated. In this scheme, the instability caused by model competition between comb filtering of the Sagnac interferometer loop mirror and self-seeded cascaded stimulated Brillouin scattering in the fiber cavity is successfully mitigated by the self-stability mechanism in the highly nonlinear fiber. Fifteen stable laser lines within 3 dB flatness are obtained at a pump power of 550 mW. We believe this can be further improved and the cavity structure further simplified by optimizing the design of the erbium-doped fiber and improving pump efficiency. However, stable multi-wavelength operation cannot be obtained by using a similar linear cavity structure. Therefore, the stability mechanism of multi-wavelength fiber linear cavity lasers using highly nonlinear fiber is investigated in detail.