Fiber optic modules consist of optoelectronic devices, functional circuits, and optical interfaces. The optoelectronic devices include a transmitter and a receiver. The transmitter part inputs an electrical signal with a certain code rate, which is driven by an internal driver chip to drive a semiconductor laser diode (LD) or a light-emitting diode (LED) to emit a corresponding rate of modulated optical signal. Its internal power automatic control circuit ensures the stability of the output optical signal power.
Fiber optic modules are sensitive optical devices. When the working temperature of the fiber optic module is too high, it can cause problems such as excessive transmission optical power, receiving signal errors, packet loss, or even direct damage to the fiber optic module. When the temperature of the fiber optic module is too high, the corresponding port indicator light will be set to red, and a series of numbers—0x00000001 can be seen, indicating that the temperature of the fiber optic module is too high.
The solution is to replace the fiber optic module. After replacing the fiber optic module, wait for 5 minutes (the polling cycle of the fiber optic module is 5 minutes, and the fault recovery of the fiber optic module usually needs to be observed after 5 minutes of the status). Observe whether the status of the port alarm light and alarm status are recovered.
After replacing the new fiber optic module, if the port red light goes out, it indicates that the fiber optic module fault alarm has returned to normal. According to the working temperature, fiber optic modules can be divided into commercial grade (0°C to 70°C), extended grade (-20°C to 85°C), and industrial grade (-40°C to 85°C), with commercial grade fiber optic modules being the most widely used. However, in fact, different application environments require the selection of fiber optic modules with corresponding temperature grades, otherwise it is easy to cause abnormal fiber optic module temperature and affect normal use.
Commercial grade fiber optic modules are suitable for indoor enterprise computer rooms and data center computer rooms, while industrial grade fiber optic modules are suitable for industrial Ethernet and 5G front haul, with the former having low requirements for the reliability of fiber optic modules, and the latter having a wide range of working temperatures and high requirements for safety and reliability. In the 5G-bearing fiber optic module white paper, it is mentioned that the fiber optic module on the AAU side of 5G front haul involves outdoor applications. As the outdoor temperature varies greatly and the working environment is relatively harsh, a more superior industrial-grade fiber optic module is needed.
The above is the solution to the problem of high temperature of fiber optic modules. When choosing and using fiber optic modules, we need to clarify the usage scenarios, select the working temperature range of the fiber optic modules appropriately, and also control the temperature of the usage environment for fiber optic modules.