Sensitivity analysis of an HgCdTe based photovoltaic receiver for long-wavelength free space optical communication systems

Abstract:

We examine theoretically the performance of an Hg_0.77Cd_0.23Te based p-n photodetector/HFET optical receiver due to its possible application at 10.6 μm free space optical communication system at high bit rate. A rigorous noise model of the receiver has been developed for this purpose. We calculate the total noise and sensitivity of the receiver. The front-end of the receiver exhibits a sensitivity of −45 dBm at a bit rate of 1 Gb/s and −30 dBm at a bit rate of 10 Gb/s, and the total mean-square noise current 〈i _n ²〉 = 5 × 10⁻¹⁵ A² at a bit rate of 1 Gb/s and 〈i _n ²〉 = 10⁻¹² A² at a bit rate of 10 Gb/s, and a 3-dB bandwidth of 10 GHz.