Fault-tolerant fiber optic coupler/repeater for use in high speed data transmission and the like

Claim 1

A fault tolerant fiber optic network for transmitting analog and digital information comprised of a plurality of network nodes interconnected by optical fibers and connectors with each network node consisting of; a terminal consisting of an assembly of electronic, electrooptic, and optical elements in a suitable mechanical enclosure supplied by a power source; a primary input optical fiber connected to said terminal for conducting a primary optical signal to said terminal; bypass optical fiber(s) connected to said terminal for conducting a bypass optical signal to said terminal; a data input/output device connected to said terminal; photodetector(s) for receiving the optical signals at each terminal from the primary or bypass fiber(s); a coupler for the purpose of dividing the primary optical signal according to a predetermined ratio and sending the divided signal to the primary and bypass fiber(s); an amplifier for boosting power in the primary input fiber; a means for reshaping or retiming the primary input signal prior to amplification if required; a logic means for determining the power in the primary and bypass fiber(s) and comparing the power to a fixed or programmable reference level and accepting or rejecting the signal based upon adherence to the reference criteria; a built-in-test circuit connected to said terminal which provides an indication of a fault in a terminal or interconnecting fiber(s) and passes this information on to the other terminals of the network; and a switching means for switching the signal of the selected bypass fiber to the terminals in the event that the signal of the primary fiber does not fall within the prescribed reference level.