A Compact Low Noise Single Frequency Linearly Polarized DBR Fiber Laser at 1550 nm

A compact low noise single frequency linearly polarized distributed Bragg reflector (DBR) fiber laser based on a 1.4-cm-long homemade Er³⁺/Yb³⁺-codoped phosphate single mode glass fiber has been demonstrated. An over 50 mW stable single frequency linearly polarized fiber laser was achieved. The measured slope efficiency is more than 21.6%, and the signal-to-noise ratio (SNR) is higher than 65 dB and the laser linewidth is less than 2.0 kHz. The laser RIN is measured to be less than ?150 dB/Hz at the frequencies over 2.0 MHz, and the obtained linear polarization extinction ratio (LPER) is more than 30 dB.