As we all know, the optical transceiver with operating wavelengths of 1310nm and 1550nm are generally suitable for long-distance transmission and are connected to single-mode optical fibers, while optical transceiver with operating wavelengths of 850nm are mostly used for short-distance transmission and connected to multimode optical fibers. We have learned that the operating wavelengths are 1310nm and 1550nm. Why is the optical module suitable for medium and long-distance transmission? Next, we will describe why the 850nm optical module is mostly used for short-distance transmission.
I have talked about the loss of 1310nm and 1550nm in single-mode fiber. Generally optical transceiver with working wavelength of 850nm are connected to multi-mode fiber. Multi-mode fiber is only suitable for short-distance transmission. The price is compared with single-mode fiber. It's much cheaper. The fiber loss of multimode fiber is relatively low when the working wavelength is 850nm. The attenuation value is 2.4dB/km. The loss at 100 meters is only 0.24db. Although 1310nm and 1550nm can also be used on multimode fibers, they are only for short distances transmission.Multi-mode fiber is not suitable for long-distance signal transmission.
1310nm and 1550nm optical transceiver are not only the difference in operating wavelength, the biggest difference lies in the cost of the module. The price of the light source transmitter and signal converter matched with the 1310nm and 1550nm optical transceiver is much higher than the price of the 850nm device, so most of the multi-mode optical fibers are connected and transmitted by optical transceiver with a working wavelength of 850nm.