A Simple Mechanism to Suppress the Mode Competition for Stable and Tunable Dual-Wavelength Erbium-Doped Fiber Lasers

Abstract

A suppressant effect for mode competition of dual-wavelength lasing oscillations induced by polarization hole burning effect in an ordinary erbium-doped fiber is proposed and experimentally demonstrated. The polarization hole burning effect is introduced by an all fiber polarization controller directly fused with a segment of erbium-doped fiber. The mechanism of the all fiber polarization controller to suppress the wavelength competition is described in detail. Results show that the mechanism is helpful to obtain stable dual-wavelength lasing oscillations at room temperature in the erbium-doped fiber laser. By adjusting the comb filter, the wavelength tuning between different dual-wavelength oscillations is realized. The side mode suppression ratio of each lasing wavelength is measured to be more than 55dB. The 3dB bandwidth of each lasing oscillation is 0.01nm and the 30dB bandwidth is 0.10nm. The power fluctuation and wavelength shift are measured to be less than 0.8dB and 0.05nm over 32 minutes for all the dual-wavelength lasing oscillations obtained in the experiment.