1, different wavelengths
Generally, the wavelength of multimode light is 850nm, and the wavelength of single-mode light is mainly 13 10nm and 1550nm. Due to serious intermodal dispersion, multimode optical modules can only be used for short-distance transmission (SR). However, single-mode optical modules are mostly used for long-distance transmission of LR, er and ZR. Usually the transmission distance is less than 2km, which is called multimode module; The transmission distance is greater than 2km, which is called a single-mode module.
2, the scope of application is different
Multi-mode optical modules are mostly used in networks with relatively low transmission rate and relatively short transmission distance, such as local area networks, and usually have the characteristics of many nodes, many connectors, many detours, many connectors and couplers, and a large number of light sources per unit fiber length. Using multimode optical module can effectively reduce the network cost. Single-mode optical modules are mostly used in lines with long transmission distance and relatively high transmission rate, such as long-distance trunk transmission and metropolitan area network construction.
3. Different types of optical fibers
The single mode in the module actually only refers to the type of optical fiber. According to the transmission mode of optical module in optical fiber, it can be divided into single-mode fiber and multimode fiber.
MMF for short, the fiber diameter of multimode fiber is generally 50/ 125 m or 62.5/ 125 m.
Single-mode fiber is called SMF for short, and its diameter is 9/ 125 m.
4. Different costs
Single-mode optical modules use twice as many devices as multimode optical modules, so the overall cost of single-mode optical modules is much higher than that of multimode optical modules.
5. Different light sources
The light source of multimode optical module is light-emitting diode or laser, and the light source of single-mode optical module is narrow-band LD or LED.
6. Different transmission distances
Single-mode optical modules are often used for long-distance transmission, and the transmission distance can reach 150 to 200km. The multimode optical module is used for short-distance transmission, and the transmission distance can reach 5km.
The bandwidth potential of single-mode optical module makes it the best choice for high-speed and long-distance data transmission, which is mostly used for long-distance transmission such as LR, ER/ZR and other lines with relatively high transmission rate, such as long-distance trunk transmission and metropolitan area network construction. It has a wide range of applications, including telecommunications, cable TV, railways, military, financial securities, customs, civil aviation, shipping, electric power, water conservancy and oil fields, etc., which need high-reliability data transmission or set up IP data transmission private networks. It is the most ideal application equipment for broadband campus network, broadband cable TV network and intelligent broadband community.