Multiwavelength switchable fiber laser employing a DMD as tuning element and variable optical attenuator

Abstract

Multiwavelength switchable erbium-doped fiber laser is demonstrated by using a digital micromirror device (DMD) as an optical filter and wavelength-dependent variable optical attenuator. The spectrum can be switched from single to multiwavelength lasing output by simple adjustment of the DMD reflection pattern. The mode competition in a fiber ring is efficiently suppressed by finely modulating the reflection column to balance the diffraction loss and EDF gain on each wavelength. The results show the 3 dB-bandwidth of multiwavelength lasing signal is less than 0.06 nm and the side mode suppression ratio is greater than 35 dB. The peak power fluctuation is less than 0.8 dB, and the wavelength drift is less than 0.06 nm over 50 min. The multiwavelength generation from the DMD-based tunable fiber laser is stable, flexible and fast.