A Novel Switchable Dual-Wavelength Ring Erbium-Doped Fiber Laser Operating in single-longitudinal-mode

In this paper, we demonstrate a simple switchable dual-wavelength ring erbium-doped fiber laser operating in single-longitudinal-mode (SLM) at room temperature. A pair of reflection type short-period fiber Bragg gratings (FBGs) is used as the wavelength-selective component of the laser. A segment of unpumped polarization maintaining erbium-doped fiber (PM-EDF) is acted as a narrow multiband filter. By turning the polarization controller (PC) to balance the gain and loss in the ring cavity, single-wavelength and dual-wavelength laser oscillations are observed. The output power variation is less than 0.6dB for both wavelengths over a five-minute period and the optical signal to noise (ONSR) is greater than 50dB.