Towards Cryophotonics: Experimental Characterization of SOA at Cryogenic Temperatures

We present an experimental system study of the influence of cryogenic temperatures on the performance of a commercial Semiconductor Optical Amplifier (SOA) over the range 240 K – 70 K. Significant performance improvements were observed when the SOA is in cryogenic conditions. At 70 K and 100 mA we were able to measure a gain as high as 52 dB. At 240 K, only 50 mA of input current are necessary to reach a gain of 37 dB, and a noise figure of 3.8 dB, close to the theoretical limit. The SOA efficiency at power saturation, rises from 2.2% at ambient temperature up to 41% at 100 mA and 120 K.