Stable multi-wavelength erbium-doped fiber laser based on a photonic crystal fiber Sagnac loop filter

A multi-wavelength erbium-doped fiber laser based on a Sagnac loop fiber which is formed by a birefringent and highly nonlinear photonic crystal fiber (PCF), a 3-dB optical coupler and two polarization controllers is proposed. The PCF Sagnac loop filter is used as comb filter and power-stabilizing and equilibrizing component in the multi-wavelength erbium-doped fiber laser. Stable multi-wavelength lasing at room temperature is achieved, owing to the contributions of both the birefringent property and the four-wave mixing effect of the PCF.