As we all know, "OM" stand for optical multi-mode, that is, optical mode, is a standard for multi-mode fiber to indicate fiber level. The bandwidth and maximum distance of different grades of transmission are different, but there are often friends who have questions about the difference between fiber jumpers OM1, OM2, OM3 and OM4. Now I will explain the fiber jumpers OM1, OM2, OM3 and OM4. The difference.
1. Comparison of parameters and specifications of OM1, OM2, OM3 and OM4 fibers
1.OM1 refers to 50um or 62.5um core diameter multimode fiber with 850/1300nm full injection bandwidth above 200/500MHz.km;
2.OM2 refers to 50um or 62.5um core diameter multimode fiber with 850/1300nm full injection bandwidth above 500/500MHz.km;
3. OM3 is a 50um core diameter multimode fiber optimized by 850nm laser. In 10Gb/s Ethernet using 850nm VCSEL, the fiber transmission distance can reach 300m;
4. OM4 is an upgraded version of OM3 multimode fiber, and the fiber transmission distance can reach 550m.
2. Design comparison of OM1, OM2, OM3 and OM4 fiber
1. Traditional OM1 and OM2 multi-mode fibers are based on LED (Light Emitting Diode) light sources in standard and design, while OM3 and OM4 are optimized on the basis of OM2, making them suitable for light sources at the same time LD (Laser Diode laser diode) transmission;
2. Compared with OM1 and OM2, OM3 has higher transmission rate and bandwidth, so it is called optimized multimode fiber or 10G multimode fiber;
3. OM4 is optimized on the basis of OM3 and has better performance.
3. Comparison of functions and features of OM1, OM2, OM3 and OM4 fibers
1. OM1: The core diameter and numerical aperture are large, with strong light collection ability and bending resistance;
2. OM2: The core diameter and numerical aperture are relatively small, which effectively reduces the modal dispersion of the multi-mode fiber, significantly increases the bandwidth, and reduces the production cost by 1/3;
3. OM3: The flame-retardant skin is used to prevent the spread of flame, prevent the emission of smoke, acid gas and poisonous gas, etc., and meet the needs of 10 gb/s transmission rate;
4. OM4: Developed for VSCEL laser transmission, the effective bandwidth is more than double that of OM3.
4. Application comparison of OM1, OM2, OM3 and OM4 fiber
1. OM1 and OM2 have been widely deployed in buildings for many years, and support Ethernet transmission with a maximum of 1GB;
2. OM3 and OM4 optical cables are usually used in the wiring environment of data centers, supporting 10G or even 40/100G high-speed Ethernet transmission.
5. When to use OM3 fiber jumper?
OM3 optical fiber is an optical fiber designed to work with VCSEL. It conforms to the ISO/IEC11801-2nd OM-3 optical fiber specification and meets the needs of 10 Gigabit Ethernet applications. There are many types of OM3 fiber, including indoor type, indoor/outdoor versatility, etc. The number of fiber cores ranges from 4 to 48. In addition, it supports all applications based on the old multimode 50/125 fiber, including support for LED light sources and laser light sources.
1. The transmission distance of Gigabit Ethernet using OM3 optical fiber system can be extended to 900 meters, which means that users do not need to use expensive laser devices when the distance between buildings exceeds 550 meters.
2. Within 2000 meters, standard 62.5/125μm multimode fiber can be used in various situations in the OC-12 (622Mb/s) rate range, except for single mode fiber. However, the emergence of OM3 multimode fiber has changed this situation. Because OM3 fiber can increase the transmission distance of Gigabit and 10 Gigabit systems, using 850nm wavelength optical modules in conjunction with VCSELs will be the most cost-effective cabling solution.
3. When the link length exceeds 1000 meters, single-mode fiber is still the only choice at present. Single-mode fiber can achieve a transmission distance of 5 kilometers at a wavelength of 1310nm in a gigabit system, and 10 kilometers in a 10-Gigabit system. Transmission distance.
4. When the link length is less than or equal to 1000 meters, OM3 50μm multimode fiber can be used in the gigabit system, and single-mode fiber should be used in the 10G system.
5. When the link length is less than 300 meters, OM3 multimode fiber can be used in any Gigabit and 10 Gigabit systems.
6. When to use OM4 fiber optic patch cords?
For a typical link, the cost of the optical module is about very expensive. Although the cost of single-mode fiber is cheaper than that of multi-mode fiber, the use of single-mode fiber requires a very expensive 1300nm optical module. Its cost is about 2-3 times that of 850nm multi-mode optical module. In general, a multi-mode fiber The cost of the system is much lower than that of a single-mode fiber system.
When investing in fiber optic cabling, if you can consider increasing the initial investment of some wiring, using better multimode fiber, such as OM4 fiber, you can ensure that the current multimode fiber technology is fully utilized and the overall cost of the current system is reduced; When you need to upgrade to a higher speed system, such as 40G and 100G, OM4 can still be used and will save costs. In short, when the transmission rate is greater than 1Gb/s, the use of multimode fiber is a good system choice. When the system requires a higher transmission rate, the following are our guiding principles for choosing OM4 fiber:
1. For Ethernet users, in 10Gb/s system transmission, the transmission distance can reach 300m to 600m; in 40Gb/s and 100Gb/s systems, the transmission distance is 100m to 125m.
2. For campus network users, OM4 fiber will support 4Gb/s fiber link length of 400m, 8Gb/s fiber link length of 200m or 16Gb/s fiber link length of 130m.
to sum up
Multimode fiber technology has evolved from OM1 multimode to OM4 that now supports 10Gbps. This will enable users to get the most effective return on their investment and become the best choice for backbone cabling or fiber to the desktop.
