Optical transceivers used in data communications equipment are typically bidirectional and require two-way communications in order to maintain their operability. However, in some applications such as cable television, the traffic is highly unbalanced with very high bandwidth requirements in one direction and minimal bandwidth requirements in the opposite direction. Hence for such efficient and cost effective one-way communication applications, unidirectional fiber optic transceivers are useful. There is provided here a unidirectional transceiver provided internally with a keep-alive signal generator to enable unidirectional transmissions. The keep alive signal is, for instance, idle characters for a Gigabit Ethernet communication system, or any other suitable handshake signal which provides the desired operability.