Study on the temperature dependent characteristics of O-band bismuth-doped fiber amplifier

We report the temperature dependent performance of an O-band bismuth (Bi)-doped fiber amplifier (BDFA) in the temperature range from -60 to +80°C. At room temperature, maximum gains of 27 and 40 dB with noise figures (NFs) of 4.3 and 4.8 dB are measured for -23  dBm signal power in the single and double pass BDFA, respectively. An increment in gain and reduction in NF is observed as the ambient temperature of the BDFA is reduced. In the double pass BDFA, the temperature dependent gain coefficient from -60 to +80°C is found to be around -0.02 and -0.03  dB/°C across the wavelength band of 1300-1360 nm for -10 and -23  dBm signal powers, respectively. We also study the gain and NF characteristics with pump power and signal power at different temperatures, and a maximum gain of 45 dB is obtained at -60°C for -30  dBm signal power.