An optical module usually consists of an optical transmitting device (TOSA, including a laser), an optical receiving device (ROSA, including a photodetector), functional circuits,main control circuit board (PCBA), housing and optical (electrical) interface and other. An optical module usually consists of an optical transmitting device (TOSA, including a laser), an optical receiving device (ROSA, including a photodetector), functional circuits,main control circuit board (PCBA), housing and optical (electrical) interface and other. The optical module serves as a crucial component in optical fiber communication systems, operating at the physical layer, which is the lowest layer in the OSI model. Its primary function is to achieve optoelectronic conversion by converting electrical signals into optical signals and vice versa. An. An optical module is a critical component in modern optical communication systems, directly affecting transmission stability, network reliability, and operational efficiency. However, during installation and daily operation, various issues may arise. Operating at the physical layer of the OSI model, optical modules are core devices in optical. The article Digital Diagnostic Function (DDM) For Optical Modules describes that DDM function can be used for real-time monitoring and fault location of the module's working status, in which the optical module's transmitting optical power and receiving optical power are the key parameters for. An optical module is mainly composed of optoelectronic devices (including the optical transmitter and optical receiver), functional circuitry, and optical interfaces.