Efficient pumping scheme of Er-doped DFB fiber laser with suppressed relaxation oscillations

The scheme of erbium-doped distributed feedback fiber laser is proposed, which combines pumping schemes of the single frequency oscillator and optical signal amplifier. The scheme provides maximum efficiency of pump to signal conversion while minimizing the effect of relaxation oscillations on the output radiation parameters. In this scheme single-frequency fiber laser radiation power up to 30 mW achieved at the pump power of 600 mW at 980 nm. Amplified spontaneous emission was at the level of 0.08%. The magnitude of the relative intensity noise is - 140dB/Hz at frequencies more than 10 MHz and - 100dB/Hz at the peak of relaxation oscillations. The linewidth of the laser radiation is less than 1 kHz.