This article provides an in-depth analysis of two key performance indicators of optical modules: transmitter power and receiver sensitivity. As an essential component of optical fiber communication, optical modules are optoelectronic devices that facilitate the conversion between optical and electrical signals during the transmission process. As data center operators accelerate upgrades in preparation for 5G. 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 components.