The most straightforward way to identify whether your fiber optic cable is OM2 or OM3 is by its jacket color.
The Primary Indicator: Cable Jacket Color
The telltale sign for distinguishing between different types of multimode fiber optic cables, including OM2 and OM3, is the cable jacket. This outer coating protects the delicate optical fibers inside.
- OM2 fiber optic cables always have an orange jacket.
- OM3 fiber optic cables have an aqua (sometimes referred to as teal) jacket.
This color coding is a widely adopted standard in the industry, making it the easiest and most reliable visual method for identification.
Distinguishing Between Multimode Fiber Types
While the question specifically asks about OM2 and OM3, understanding the common color coding for other multimode fiber types can provide helpful context for identification.
| Fiber Type | Jacket Color | Common Applications |
|---|---|---|
| OM1 | Orange | Older 100 Mbps or 1 Gbps Ethernet networks |
| OM2 | Orange | 1 Gbps Ethernet (up to 550m), older installations |
| OM3 | Aqua | 10 Gbps Ethernet (up to 300m), 40/100 Gbps (shorter) |
| OM4 | Aqua | 10 Gbps Ethernet (up to 400m), 40/100 Gbps (longer) |
| OM5 | Lime Green | Specifically designed for future shortwave division multiplexing (SWDM) for 40/100 Gbps+ |
Note: While OM2 and OM1 share the orange jacket, they can often be differentiated by performance specifications if labels are present, or by typical installation age.
Beyond Color: Performance Characteristics
While jacket color is the most immediate identifier, the reason for different fiber types lies in their performance capabilities, particularly their effective modal bandwidth (EMB) and reach for various Ethernet speeds.
- OM2 is optimized for 1 Gigabit Ethernet, typically supporting distances up to 550 meters.
- OM3 is specifically designed for 10 Gigabit Ethernet, supporting distances up to 300 meters, and can also support 40 Gigabit and 100 Gigabit Ethernet over shorter distances. Its improved performance is due to its laser-optimized design.
Practical Tips for Identification
- Visual Inspection: Always start by checking the cable jacket color. This is the quickest and most definitive method for OM2 vs. OM3.
- Cable Labels: Many fiber cables also have labels or print on the jacket indicating the fiber type (e.g., "OM2," "OM3," "50/125 Multimode").
- Documentation: If you are dealing with a pre-existing network, consult the network documentation or cabling schematics, as these often specify the type of fiber installed.
