Simultaneous optical amplification, detection, and transmissionusing in-line semiconductor laser amplifiers

It is demonstrated that in broadband networks inline semiconductor laser amplifiers (SLAs) that provide system gain can also be used as simultaneous transceivers for additional channels at higher frequencies. In the experiment, an SLA in a 622-Mb/s baseband system provided a 6.5-dB fiber-to-fiber gain and served simultaneously as a receiver and a transmitter for two frequency-shift-keying (FSK) channels (each carrying 10 Mb/s) at 755 and 1075 MHz, respectively. Such optical amplifiers/transceivers are potentially useful in broadband digital networks with out-of-band signaling channels or in subcarrier multiple-access networks