Multi-protocol dual fiber link laser diode controller and method

A dual optical fiber transceiver, for use with first and second optical fibers, includes a laser transmitter for transmitting laser light into the first optical fiber, a laser light receiver for receiving laser light from the second optical fiber, and a controller coupled to the laser transmitter and laser light receiver. The controller includes a multi-protocol state machine for establishing the full duplex connection whenever the other device operates in compliance with either (A) a predefined "on-off-on" signaling protocol for establishing full duplex connections, or (B) a second predefined signaling protocol for establishing full duplex connections. In a preferred embodiment, the predefined "on-off-on" signaling protocol is the Open Fiber Control (OFC) protocol and the second predefined signaling protocol is a standard "laser transmitter always on" protocol. In the preferred embodiment, the multi-protocol state machine disables operation of the laser transmitter whenever a loss of light condition is detected by the transceiver's laser light receiver that is not in compliance with the OFC protocol.