Detailed analysis of SFP optical module interface indicators and components

1. Output optical power Output optical power refers to the output optical power of the light source at the sending end of the optical module, in dBm.

2. Received optical power Received optical power refers to the received optical power at the receiving end of the optical module, in dBm.

3. Receiving sensitivity Receiving sensitivity refers to the minimum received optical power of the optical module at a certain rate and bit error rate, in dBm. In general, the higher the rate, the worse the reception sensitivity, that is, the greater the minimum received optical power, and the higher the requirements for the optical module receiver devices.

4. Saturated optical power, also known as optical saturation, refers to the maximum input optical power when maintaining a certain bit error rate (10-10~10-12) at a certain transmission rate, in dBm.

It should be noted that the photodetector will appear photocurrent saturation under strong light. When this phenomenon occurs, the detector needs a certain time to recover. At this time, the receiving sensitivity decreases, and the received signal may be misjudged, causing bit error. In addition, it is very easy to damage the detector at the receiving end. In use and operation, it should be prevented from exceeding its saturated optical power as much as possible.

Note that for long-distance optical modules, since the average output optical power is generally greater than its saturated optical power, users should pay attention to the length of optical fiber when using it to ensure that the actual received optical power arriving at the optical module is less than its saturated optical power, otherwise it may cause damage to the optical module.