Single fiber modules (BiDi) use one fiber for both transmitting and receiving data. They use a thin fiber. When designing or upgrading a fiber network, one key decision is whether to use dual-fiber or single-fiber (BiDi) optical modules. Both have their own characteristics and are suited to different scenarios. 🔍 Basic Differences ⚠️. Dual-fiber bidirectional Mux is a key component in dual fiber systems and is commonly deployed in long-distance, high-capacity optical networks, such as C/DWDM backbone networks. Its support for full-duplex transmission, low interference, and stable wavelength isolation makes it ideal for ensuring. Common wavelength of dual fiber optical module The advantages of BIDI module: BIDI optical module is relatively expensive in unit price, but save fiber resources, only need one fiber.