High gain O-band bismuth-doped fiber amplifier based on signal and pump dual-pass structure

Abstract

Due to the tendency of data traffic approaching the current capacity limit, the development of a high-performance o-band amplifier has become an important topic. In this paper, we construct a model of the dual-pass BDFA and compare it with the single-pass BDFA. In addition, the effect of the loss of the reflected part of the dual-pass structure on the gain is analyzed by numerical simulation. Utilizing the theory to guide the experiment, a reflector-based signal and pump dual-pass O-band bismuth-doped phosphosilicate fiber amplifier is proposed. The amplifier experimentally obtained a maximum net gain of 41.8 dB at 1325 nm with a noise figure (NF) of 5.8 dB under the total pump power of 1050 mW and the input signal power of −34 dBm. The 3 dB saturation output signal power of the BDFA is 16.8 dBm at a total pump power of 1050 mW, at which point the signal input power is –22 dBm and the NF is 6.6 dB. The gain coefficient is 0.064 dB/mW at the input signal power of −30 dBm. The measured 3 dB and 10 dB net gain bandwidths of this amplifier are 30 nm (1312–1342 nm) and 58 nm (1300–1358 nm), respectively.