Tunable Multiwavelength Er-Doped Fiber Laser With a Two-Stage Lyot Filter

Abstract

A switchable and tunable multiwavelength erbium-doped fiber laser is proposed and demonstrated based on a two-stage Lyot filter and intensity-dependent loss (IDL) effect induced by a nonlinear optical loop mirror (NOLM). The proposed laser can achieve multi-parameter individually tuning functions, such as adjusting the channel-spacing, number, and spectral-range of lasing line. The channel spacing can be switched via adjusting the beam's polarization in the Lyot filter among 0.53, 0.78, and 1.56 nm. Meanwhile, the number and the spectral range of the multiwavelength lasing line can be independently controlled by IDL modulation through the combination of adjusting pump power and the birefringence in the loop of the NOLM. The individual tuning method of the proposed laser on each specific output characteristic provides more convenience and practicality to the applications.