Switchable Dual-wavelength Erbium-doped Fiber Laser with High OSNR and Stability Using PM-FBG and CFBG

A switchable dual-wavelength linear-cavity erbium-doped fiber laser based on a polarization maintaining fiber Bragg grating (PM-FBG) and a chirped FBG (CFBG) is proposed and experimentally demonstrated. Due to the polarization hole burning (PHB) effect introduced by the PM-FBG, the laser designed can operate in stable dual-wavelength mode with a wavelength spacing of 0.667 nm or easily switch to single-wavelength lasing mode by adjusting a polarization controller at room temperature. The optical signal to noise ratio (OSNR) of the dual-wavelength output is >70 dB, and the wavelength fluctuation and power fluctuation are less than 0.02 nm and 0.04 dB respectively for both wavelengths during an experimental time of 30 minutes. In addition, the wavelength shifts with temperature tuning is also investigated.