Experimental studies on dual-wavelength all-optical gain-clamped erbium-doped fiber amplifier

We have proposed a novel scheme which uses the fiber loop mirror (FLM) in the feedback loop as a filter to realize the dual-clamping EDFA, and carried out the related experiments. A dual-oscillating laser with wavelengths of 1533.2 nm and 1559.05 nm is obtained by controlling the pump power and adjusting the cavity losses and the FLM Gain-clamping experiments with signals wavelengths of 12 nm and 13 nm are demonstrated when the FLM works under both reflective and transmissive states. For the 1540 nm signal, the gain ripple is no more than 0.3 dB when the input power is less than -14.88 dBm; For the 1550 nm signal, the gain ripple is no more than 0.1 dB when the input power is less than -16.51 dBm The experimental results have shown that all optical gain-clamped mechanism could be realized by using both reflective FLM and transmissive FLM. Moreover, the characteristics of output pulse by these two schemes are almost uniform, which indicate they have equivalent effects on gain clamping.