Switchable Multi-Wavelength Erbium-Doped Fiber Laser With Adjustable Wavelength Interval

Abstract

A switchable multi-wavelength erbium-doped fiber laser based on parallel dual Lyot filters is experimentally demonstrated in this paper. A new type of parallel-structure fiber filter is designed and its spectrum is simulated. The structure is simple. The spectra of the filter changes when adjusting the polarization states of the polarization controllers. Due to the characteristics of the filter spectra and wavelength competition, the output wavelengths can be single wavelength, dual wavelengths, and triple wavelengths. When the output is single wavelength, the lasing wavelength is tunable with a tuning range of ∼13 nm. The wavelength interval of dual wavelengths can be adjusted from 3.03 to 17.15 nm, which is a relatively wide range. The interval of three wavelengths also changes to some extent. Moreover, the optical signal-to-noise ratios of the output wavelengths can be up to 47 dB.