1, the appearance of the use: single-fiber optical module only a fiber interface to connect a fiber patch cord, dual-fiber optical module has two fiber interfaces to connect two fiber patch cords. In DWDM implementations, each direction of communication occupies a dedicated fiber, improving the stability of the transmission. How do we choose, and what are their differences and advantages? Let's learn about this! What is a Single-Fiber (BiDi) Transceiver? Single fiber module also called BiDi transceiver or WDM module. Single Fiber Optical Transceivers: In this device, the transmission and reception of data happens on a single fiber. Technically, it requires only half of the actual length of the optical fiber. Single mode fiber media converter act as a photoelectric.