Output optical power refers to the output optical power of the light source at the transmit end of the optical module. Among them, W or mW is a linear unit, and dBm is a logarithmic unit. By understanding the measurement standards, influencing factors, and application. SFP (Small Form-factor Pluggable) optical modules are compact, hot-pluggable transceivers that enable network equipment to connect seamlessly to fiber and copper links. These modules, including SFP, SFP+, and SFP28, are widely used in enterprise networks, data centers, and carrier-grade deployments. When designing optical networks, understanding the TX/RX power range is vital for ensuring optimal performance and long-term reliability. The TX (transmit) and RX (receive) power levels significantly affect everything from signal strength to transmission distances and the overall optical power.