Experimental comparison study of the performance of reflector-based O-band BDFA under different pumping schemes

Abstract

A bismuth-doped fiber amplifier (BDFA) operating in O-band with a double-pass structure in combination with a reflector is experimentally compared in detail under three pumping schemes. Different pump powers and signal input powers are used to investigate the effect on gain and noise figure (NF). The results show that not all wavelengths in the O-band but only wavelengths in the 60 nm range (1290 nm-1350 nm) can be improved with a double-pass, where the improvement is most prominent at 1320 nm; The gain improvement can only be obtained with a double-pass when the signal is input with low-power (approximately below −7 dBm). Among the three pumping schemes, the gain enhancement is most prominent with bidirectional pumping. A maximum gain of 31 dB was achieved at 1320 nm for −20 dBm input signal in double-pass with the pump power of 500 mW under bidirectional pumping scheme, which is an improvement of nearly 25.4% compared to single-pass. In addition, compared to forward and backward pumping also improved by 5.7% and 23.8%. This work demonstrates that the performance of O-band BDFAs can be effectively enhanced by reflectors, which have positive practical significance and reference value.