Impact of input signals on the bit error rate performance of semiconductor-laser-amplifier-based switch systems

The impact of input signal power and polarisation states on the bit-error-rate (BER) performance of semiconductor-laser-amplifier (SLA) based switch systems has been investigated theoretically and experimentally. The theoretical calculation was based on a single-stage SLA-switch model and may be extended to apply to a multistage switch matrix with identical parameters for each stage. The calculations are in good agreement with the experimental results, which indicate that, for a conventional direct detection receiver working at 2.5 Gbit/s data rate, it is necessary to operate an SLA switch with input power of approximately -20 dBm, or more, to get an overall BER penalty of less than 1 dB