The full name of the optical module is optical transceiver, which is an important device in the optical fiber communication system. It is responsible for converting the received optical signal into an electrical signal, or converting the input electrical signal into a stable optical signal at a corresponding rate.
The optical module is composed of optoelectronic devices, functional circuits and optical interfaces. The optoelectronic devices include two parts: transmitting (TOSA) and receiving (ROSA).
The key technical parameters of the optical module include average transmitted optical power, extinction ratio, receiving sensitivity, and saturated optical power.
1. The average transmitted optical power refers to the arithmetic mean of the optical power when the signal logic is 1 and the optical power when it is 0.
2. The extinction ratio refers to the ratio of the average transmitted optical power of all "1" codes to the average transmitted optical power of all "0" codes. It will affect the receiving sensitivity. The extinction ratio should be controlled within a reasonable range. A large extinction ratio is conducive to reducing Power penalty, but too large will increase the pattern-related jitter of the laser.
3. Receiving sensitivity refers to the minimum limit that the receiving end can receive the signal. When the signal energy of the receiving end is less than the standard receiving sensitivity, the receiving end will not receive any data.
4. The saturated optical power value refers to the maximum detectable optical power at the receiving end of the optical module, generally -3dBm. When the received optical power is greater than the saturated optical power, bit errors will also be generated. Therefore, if the optical module with high transmitting optical power is tested without attenuation and loopback, bit errors will occur.
