Multiwavelength Er-Doped Fiber Ring Laser Incorporating Highly Nonlinear Fiber

We demonstrate a multiwavelength Er-doped fiber ring laser using a fiber Fabry–Perot interferometer as the comb filter. By simply incorporating a highly nonlinear fiber (HNLF), multiwavelength lasing over a wavelength range of 40 nm is achieved at room temperature. We found that the self-phase modulation (SPM) and the four-wave mixing (FWM) in the HNLF enables the multiwavelength lasing.