Low-noise optical detection of a 1.1 Gb/s optical data stream

A low-noise, 1.1 Gb/s optical receiver has been built using a silicon a.p.d. and a GaAs f.e.t. The receiver sensitivity was evaluated using error-rate measurements, and for a bit error rate of 10¿9, with no fibre, the measured optical sensitivity was ¿37.0 dBm. These results are used as a basis for the calculation of maximum repeater spacings for 1.1 Gb/s systems operating at 0.85 ¿m and 1.25 ¿m wavelengths.