A system for use in carrying out downhole coiled tubing applications with two-way telemetry over a single fiber optic thread. The system includes uphole and downhole assemblies each having unique couplers. Specifically, the couplers may be configured to secure the single fiber optic thread at one end thereof while having dedicated fiber optic channels at another side thereof for interfacing a fiber optic transmitter and receiver. Thus, fiber optic data may travel from a surface assembly over the thread for detection at the downhole assembly simultaneous with fiber optic data travelling from the downhole assembly to the surface assembly over the same thread.