The fiber size of the single-mode optical module is 9-10/125 m, which has the characteristics of unlimited bandwidth and lower loss compared with the multi-mode optical fiber. It is mainly used for long-distance transmission and can reach 150 to 200km. LD or LED with narrow spectral lines are used as the light source.
Concept
The single mode in the optical module actually refers only to the type of optical fiber. Single-mode optical module is an optical module used with single-mode optical fiber. The LED with a narrow LD or spectral line is used as the light source, which can transmit extremely high bandwidth data signals, so the transmission distance is very long. The logo on the single-mode optical module is "SM", and the optical fiber is yellow, mainly with the wavelength near the window of 1310nm and 1550nm.
Application
The bandwidth potential of single mode optical module makes it the best choice for high-speed and long-distance data transmission. It is mainly used for LR, ER/ZR and other long-distance transmission and relatively high transmission rate lines, such as long-distance trunk line transmission and man construction. Application field widely, including telecom, cable TV, railways, military, financial securities, customs, civil aviation, shipping, electric power, water conservancy, oil field and so on all kinds of broadband data network and require high reliability of data transmission or set up IP data transmission private network, is broadband network, broadband cable network and intelligent broadband optical fiber, optical fiber to the building the village to be the most ideal equipment.
Single mode optical module operating equipment
Single-mode optical module fiber is cheap, but single-mode equipment is much more expensive than similar multi-mode equipment. Single-mode equipment can operate on both single-mode and multi-mode optical fibers, while multi-mode equipment is limited to multi-mode optical fibers.
Notes for use of long distance single mode optical module
Long distance single-mode optical module has strict requirements on the power range of receiving light. If the receiving sensitivity is exceeded, the optical module will fail.
1. Don't immediately after a long single mode optical mode to equipment installation to connect optical fiber, to use the command line display transceiver diagnosis interface read module to receive light emitting power, check to see if the luminous power within the normal range, light power is not + 1 dB and outliers, didn't connect optical fiber to software usually display receive light power may be - 40 dB or lower value.
2. Under the condition of conditions, it is recommended to use the optical power meter to test the receiving and luminescent power. Only in the normal receiving range can the optical fiber be connected to the long-distance single-mode optical mode.
3. Under no circumstances can the optical fiber be directly looped to test the long-distance single-mode optical mode. If necessary, the optical attenuator must be connected to make the received optical power within the receiving range to conduct the loopback test.
4. If long-distance single-mode optical mode is used, the received power must have a certain margin. The actual received power is more than 3dB reserved compared with the receiving sensitivity.
5. In general, multi-mode optical module and multi-mode optical fiber use, single-mode optical module and single-mode optical fiber use, if one side is multi-mode equipment, one side is single-mode optical fiber, single multi-mode converter. If the transmission distance is very short, the single-mode optical module can be temporarily replaced by the multi-mode optical module, but not the other way around, because the laser spot of the multi-mode optical module is very large, with 62.5nm or 50 m, while the fiber core of the single-mode optical fiber is only 9 m, so the emitted light of the module cannot be coupled into the single-mode optical fiber.
