How to identify multimode fiber optic cable models

Multimode fiber optic cables can be identified by their core size, jacket color, labeling, and performance specifications such as OM1 through OM5.Key Identification Methods1. Jacket ColorOM1: Typically orange; core size 62.5 µm; used for 100 Mb/s to 10 Gb/s over short distances .OM2: Usually grey (sometimes legacy orange); core size 50 µm; supports 1 Gb/s to 10 Gb/s .OM3: Aqua; 50 µm core; laser-optimized for 10–40 Gb/s .OM4: Aqua or sometimes violet; 50 µm core; higher bandwidth than OM3, suitable for 10–100 Gb/s .OM5: Lime green; 50 µm core; supports wideband multimode applications and multiple wavelengths . 2. Core Size and BandwidthOM1: 62.5 µm core, 200 MHz·km at 850 nm.OM2: 50 µm core, 500 MHz·km at 850 nm.OM3: 50 µm core, 2000 MHz·km at 850 nm.OM4: 50 µm core, 4700 MHz·km at 850 nm.OM5: 50 µm core, same modal bandwidth as OM4 at 850 nm but optimized for multiple wavelengths . 3. Cable Labeling Check the printed markings on the cable jacket:Example: “OM3 50/125” indicates a 50 µm multimode fiber optimized for laser transmission.Example: “OM1 62.5/125” indicates a 62.5 µm multimode fiber . 4. Light Source CompatibilityLED sources: Typically used with OM1 and OM2 fibers.Laser-optimized fibers: OM3, OM4, and OM5 are designed for VCSEL lasers, supporting higher data rates over longer distances . 5. Tools for VerificationOptical power meters and fiber identifiers can confirm the fiber type by measuring attenuation and modal bandwidth.Microscope inspection can verify core diameter if the jacket color or labeling is unclear .Practical TipsAlways cross-check jacket color with printed labels, as some legacy cables may not follow current color standards.For new installations, prefer laser-optimized OM3/OM4/OM5 for high-speed data centers.Use OM1/OM2 only for legacy systems or short-distance applications. By combining jacket color, core size, labeling, and light source compatibility, you can reliably identify the type of multimode fiber optic cable and ensure proper network performance .