Fiber optic module is an important component in fiber communication, and only by ensuring its stable operation can we ensure the normal operation of optical network. So how does temperature affect fiber optic modules?
The operating temperature has a great impact on the use of fiber optic modules. If the operating temperature of the fiber optic module is too high or too low, the optical power will generally decrease, the sensitivity will decrease, and the eye diagram will deteriorate. In addition, it will accelerate the aging of internal devices, reduce the life of the fiber optic module, and even directly cause damage to the optical devices in severe cases.
Generally, when the operating temperature of fiber optic modules rises, the optical power will decrease, and the APC (automatic power control circuit) will maintain the stability of the optical power of the fiber optic module. However, if the temperature continues to rise, the APC will lose control, and the bias current will increase sharply. If it exceeds the monitoring value, it will automatically lock, and eventually burn out the driving chip or TOSA.
The operating temperature specifications of fiber optic modules are divided into commercial grade (0 to 70℃), extended grade (-20℃ to 85℃), and industrial grade (-40℃ to 85℃), but the most commonly used is the temperature range of commercial and industrial grade.
We should choose the operating temperature of fiber optic modules according to the actual use environment. If it is used in data centers, enterprise machine rooms, we can use commercial-grade fiber optic modules, because air conditioning will be installed inside the data center and machine room to maintain indoor temperature stability. If it is used in environments with large temperature changes such as outdoors, remote mountainous areas, and tunnels, we need to use industrial-grade fiber optic modules, which will introduce temperature compensation software. Its function is used to ensure a stable working current supply for fiber optic modules. When the temperature changes, the temperature compensation software will take effect.
Nowadays, fiber optic modules can support DDM function to monitor the temperature, transmit power, receive power, current, voltage and other parameters, as well as temperature compensation. If it is not within the normal range, DDM alarm will occur. Each fiber optic module has temperature compensation function, which is automatically controlled by APC circuit and will change with temperature changes. Usually, commercial-grade fiber optic modules will not have high temperature in the working environment of 0-70℃, and DDM alarm will occur if the temperature is too high. Finally, when purchasing fiber optic modules, be sure to pay attention to choosing the corresponding grade fiber optic modules according to the use environment, so as to ensure the stable operation of fiber optic modules.
