Stable Single Polarization, Single Frequency, and Linear Cavity Er-Doped Fiber Laser Using a Saturable Absorber

A simple approach for stable single polarization, single frequency, and linear cavity erbium doped fiber laser is proposed and demonstrated. A Fabry–Pérot filter, polarizer and saturable absorber are used together to ensure stable single frequency, single polarization operation. The optical signal-to-noise ratio of the laser is approximately 57 dB, and the Lorentz linewidth is 13.9 kHz. The polarization state of the laser with good stability is confirmed and the degree of polarization is >99%.