All-optical semiconductor switching devices for applications in optical communication systems

We report on all-optical interferometric switches for applications as demultiplexer and add/drop multiplexer in high bit-rate optical communication systems based on the optical time-division multiplexing technique. We focus the discussion on a novel switch called Gain-Transparent-SOA switch. The key element of the Gain-Transparent-SOA switch is a semiconductor optical amplifier (SOA), which is transparent for the data signal. On the other hand, the injection of optical control pulses in the SOA causes a phase modulation of the data signal. The new switch provides high linearity, high switching contrast, low noise, wide bandwidth, and low crosstalk. The switch was tested experimentally at data rates up to 640 Gbit/s.