The optical link budget in SFP modules refers to the total amount of optical power loss (measured in dB) that a fiber optic link can tolerate while still maintaining reliable communication between the transmitter and receiver. It represents the module's ability to operate reliably across an optical. This is related to the optical fiber loss. The loss is minimal around 850nm, increases between 900 ~ 1300nm, decreases again at 1310nm, and reaches its lowest at. In order to measure optical loss, you can use two units, namely, dBm and dB. Both affect network performance but in different ways. Choosing the right components, connectors, and transceivers depends on knowing these.