Views: 0 Author: Site Editor Publish Time: 2023-04-06 Origin: Site
When buying the optical module, we will consider the transmission distance. The manufacturer will match the transmission distance we need. The transmission distance of the light module is divided into short distance, medium distance and long distance. Different light modules have different transmission distances. The single -mode optical module and the single -mode fiber are coordinated with a mid -distance transmission. The multi -mode optical module and multi -mode fiber are coordinated with a short distance transmission. The longest transmission distance of the multi -mode fiber is 2km, and the single -mode optical fiber can transmit a maximum transmission of 160km. The calculation of these transmission distance must be accurately calculated, so how to calculate the transmission distance of the optical module?
The optical module transmission business must pass through the optical fiber, but the transmission process must have transmission loss, which is generally called fiber attenuation. There are three main factors affecting the distance transmission distance: transmitting light power, receiving sensitivity, and fiber attenuation. The attenuation of optical fibers is also related to the actual choice of optical fiber.
Generally, the single -mode fiber is G.652, and the 1310NM working wavelength loss is about 0.35DB per kilometer, and the loss of 1550nm working wavelength per kilometer is about 0.22dB. Damage distance = (transmitting light power-receiving sensitivity)/fiber attenuation. Therefore, the limit transmission distance of the calculation of the optical module is easy now. Taking the ordinary Gigabit light module as an example, the optical power is -3 ~ -9DB, the receiving sensitivity is -3 ~ -22DB, the limit value is -3- (-22) = 18dB, 18db ÷ 0.35db/km = 51.428km, That is, the Gigabit 1310Nm only considers the optical fiber loss to transmit up to 51km, but in practical applications, in addition to the fiber loss, there are other losses, including bending losses, felting loss, connection or coupling loss. Therefore, the Gigabit 1310Nm light module with a mega 1310Nm light module is to remove external loss. In order to prevent the signal instability and packet loss of light road transmission, the limit distance will not be selected during the process of purchasing the optical module, and a certain amount of balance will be left. For example, the Gigabit 1310NM40km can be transmitted with a working wavelength of 1550nm.
