BiDi single fiber bidirectional optical module full analysis

The interfaces of optical modules are mainly divided into single-fiber bidirectional BiDi, dual-fiber bidirectional (Deplux) and other types. In the wavelength division multiplexing system, the line transmission methods mainly use single-fiber unidirectional and single-fiber bidirectional. In this article, ETU-LINK will focus on analyzing BiDi single-fiber bidirectional optical modules.

Single-fiber bidirectional, also known as BiDi (Bidirectional), means that optical signals in two directions can be sent and received simultaneously in one optical fiber. The conventional optical fiber transmission is single-fiber and one-way, and two optical fibers are needed to realize two-way communication. In contrast, BiDi technology only needs one optical fiber, which means that the transmission capacity of the existing optical fiber is increased by one. times, thereby saving fiber resources.

But for BiDi optical modules, the optical modules at both ends of the link must be used in pairs. Generally, the optical module has two ports for transmitting and receiving, while the BiDi optical module has only one port, which is filtered by the filter in the optical module, and simultaneously transmits the TX optical signal and receives the RX optical signal or vice versa.

The dual-fiber optical module has only one wavelength, usually 850nm, 1310nm, 1550nm, etc. Single-fiber optical modules have two different wavelengths, the common ones are the following wavelengths:

The BiDi optical module has a compact structure. The optical transceiver is composed of BOSA. The components include a detector and an adapter. BOSA combines the two together. Compared with TOSA and ROSA, there are more filters and bases. BiDi optical modules currently support rates of 155M, 1.25G, 10G, 16G, 25G, 40G, 100G, etc.

Since the wavelength used by the BiDi optical module does not generate a large dispersion cost, the transmission index is no different from that of the dual-fiber bidirectional optical module, and the cost has obvious advantages, and there is no need to increase maintenance and management, so the direct fiber connection is generally A single-fiber bidirectional solution is used. At the optical module level, both BiDi optical modules and color light modules can improve the utilization of optical fibers to a certain extent, which is also a good choice for users to save costs.