This article will systematically analyze the core performance indicators of optical modules from five dimensions: transmit optical power, receive optical power, overload optical power, receiver sensitivity, and extinction ratio. Optical modules are crucial for today's communication systems as they convert electrical signals into light signals for rapid data transfer. Understanding their key parameters isn't just technical jargon – it's critical for ensuring compatibility, performance, and reliability in your data center. The Transmitter Optical Sub Assembly (TOSA) is responsible for the emission of light. It is important to note that the photodetector may experience optical. Whether you're selecting an optical transceiver module for short-range multimode applications or long-haul coherent transmission, understanding these parameters ensures reliability and performance. We'll cover everything from physical form factors to spectral characteristics, modulation formats.