The Feasibility Study of Incorporating OTDR Functionality in SFP56 Communication Optical Modules

The expansion of the construction of the 5th Generation Mobile Communication Technology (5G) has led to a rapid increase in the use of optical modules in the front transmission network. Small Form Pluggable (SFP) encapsulated optical modules are commonly used in the front transmission network. Fault points in the communication link can seriously affect the communication service of SFP56 optical modules. Traditional Optical Time Domain Reflectometer (OTDR) requires disassembly of the optical path during use, which is inconvenient and has always been a problem that needs to be solved. This article attempts to design an SFP56 communication optical module equipped with OTDR function, which can simultaneously complete communication services and OTDR measurement functions without changing the size of the optical module. On the basis of completing the basic information transmission of SFP56, it can detect event points in the line. When problems arise during use, this module can quickly locate the location of the problem for subsequent troubleshooting.The article preliminarily verifies through samples that the design meets the requirements of normal communication business indicators, with sufficient eye diagram margin; At the same time, relevant experimental verification was conducted on the measurement performance of OTDR, and it was found that the module can accurately measure attenuation and breakpoints in the communication link, basically meeting the expectations of OTDR measurement. At the same time, the reliability of the designed OTDR measurement was preliminarily verified through high and low temperature experiments. The dynamic range of OTDR measurement may slightly decrease under high temperature conditions, but there is still sufficient margin.The SFP56 optical module equipped with OTDR function basically meets the design expectations, allowing for quick switching between communication service mode and OTDR measurement mode. OTDR mode measurement event points and fiber attenuation are relatively accurate. Currently, experimental verification shows that the designed optical module can complete three temperature communication service transmission and OTDR measurement within 10km.