Multimode Fiber Optic Cable Types: OM1 vs OM2 vs OM3 vs OM4 vs OM5
For short to medium distance high speed data transport, multimode fiber optic cables are popular in data centers, enterprise networks and campus environments. There are five main types of multimode fiber, standardized by ISO/IEC 11801: OM1, OM2, OM3, OM4 and OM5. These multimode fiber types vary based on core diameter, bandwidth, maximum distance and application suitability. This article dives into this knowledge to help inform your network design and add future proofing.
Introduction to Multimode Fiber Optic Cable Types
Multimode fiber optic cables allow multiple light modes to transmit at once, making them useful for short to medium range applications like communications within buildings and campuses. The primary types of multimode fiber, OM1, OM2, OM3, OM4 and OM5, differ in terms of standardization and performance. Differences in construction and functionality mean each fiber type varies in core size, bandwidth, maximum transmission distance and typical use case. Understanding how these characteristics differ is important to select the correct fiber optic cable to maximize communication network performance and future growth. This article will explore the distinctiveness, speeds and application types associated with each multimode fiber type.
Physical and Technical Characteristics of OM1 to OM5 Fibers
The main distinctions among multimode fibers are based on the physical diameter of the core, the color of the jacket surrounding the core, the type of optical sources installed and the transmission bandwidth capacity.
Core diameter:
OM1 has a core diameter of 62.5µm, whereas OM2, OM3, OM4 and OM5 all have a core diameter of 50µm. The fact that OM2, OM3, OM4 and OM5 all have smaller physical core diameters enables higher bandwidth and longer distance transmission.
Jacket color coding:
OM1 and OM2 cables are orange. OM3 and OM4 cables are aqua. OM5 cables are lime green to signify wideband transmission capability.
Optical sources:
OM1 and OM2 use LEDs as the optical source. The use of LEDs on OM1/OM2 fibers limits bandwidth and distance. In contrast, OM3, OM4 and OM5 are “laser optimized” and use a subtype of laser called VCSEL. VCSEL enables very high speed performance and long-distance transmission.
Bandwidth:
OM1 has a maximum bandwidth of 200 MHz·km, OM2 has a maximum bandwidth of 500 MHz·km, OM3 has a maximum bandwidth of 2000 MHz·km, OM4 has a maximum bandwidth of 4700 MHz·km and OM5 has a maximum bandwidth of 28000 MHz·km. The increase in bandwidth for the new fiber types illustrates the increased capacity to transmit data.
| Fiber Type | Core Diameter | Jacket Color | Optical Source | Bandwidth (MHz·km) | Typical Use Case |
| OM1 | 62.5 µm | Orange | LED | 200 | Legacy, 100MbE |
| OM2 | 50 µm | Orange | LED | 500 | 1GbE |
| OM3 | 50 µm | Aqua | VCSEL | 2000 | 10GbE, 40/100GbE |
| OM4 | 50 µm | Aqua | VCSEL | 4700 | Extended 10/40/100GbE |
| OM5 | 50 µm | Lime Green | VCSEL | 28000 | Wideband WDM |
Maximum Distance and Data Rate Capabilities
Each type of multimode fiber provides different maximum distances at varying Ethernet speeds:
OM1 supports distances of 275m for 1 Gbps, 33m for 10 Gbps and does not support 40/100 Gbps.
OM2 supports distances of 550m for 1 Gbps, 82m for 10 Gbps and does not support 40/100 Gbps.
OM3 supports distances of 1000m for 1 Gbps, 300m for 10 Gbps and 100m for 40/100 Gbps.
OM4 supports distances of 1000m for 1 Gbps, 550m for 10 Gbps and 150m for 40/100 Gbps.
OM5 is very similar to OM4, but it supports wideband Wavelength Division Multiplexing (WDM) to transmit multiple wavelengths.
| Fiber Type | 1Gbps Max Distance | 10Gbps Max Distance | 40/100Gbps Max Distance | Notes |
| OM1 | 275 m | 33 m | Not Supported | Legacy LED fiber |
| OM2 | 550 m | 82 m | Not Supported | LED fiber |
| OM3 | 1000 m | 300 m | 100 m | Laser-optimized |
| OM4 | 1000 m | 550 m | 150 m | Enhanced OM3 |
| OM5 | 1000 m | 550 m | 150 m+ | Wideband WDM |
Multimode optical fiber has limitations on how far you can run certain data rates and how much data will be carried. Laser-optimized multimode fiber types help overcome some of these limitations.
OM1 vs OM2 vs OM3 vs OM4 vs OM5: Performance & Application Comparison
- OM1 vs OM2: The OM1 fiber type was made with a larger core diameter to be capable of running 100Mbps. However, OM2 fiber type increases bandwidth and distance for running 1Gbps.
- OM1 vs OM3: The OM3 fiber type is laser optimized to run 10Gbps and even higher speeds over larger distances.
- OM3 vs OM4: The OM4 fiber type has double the bandwidth of OM3 at the same data rates, as well as extended distances great enough to be useful for larger data centers.
- OM4 vs OM5: OM5 makes use of wideband wavelength division multiplexing (WDM) to provide multi wavelength transmission of optical data, with enough bandwidth to future proof your current and future data needs.
| Fiber Type | Speed Support | Max Distance (10Gbps) | Bandwidth | Typical Applications | Cost Considerations |
| OM1 | Up to 1Gbps | 33 m | Low | Legacy, low-speed networks | Low |
| OM2 | Up to 1Gbps | 82 m | Medium | Enterprise LAN | Moderate |
| OM3 | Up to 10Gbps | 300 m | High | Data centers | Higher |
| OM4 | Up to 10Gbps | 550 m | Very High | Extended data centers | Higher |
| OM5 | Up to 100Gbps+ | 150 m+ | Ultra High | Wideband WDM, future-proof | Highest |
Backward compatibility allows OM4 to work with OM3 equipment, making upgrades smoother for network administrators.
Multimode Fiber Connectors and Cable Construction
The most common multimode fiber connectors in today’s data centers are the LC, SC, ST and MPO. The LC connector is compact and designed for high-density environments; the SC is a mainstream and reliable connector; ST is a legacy connector preferable for field connections; MPO supports many fiber connections, allowing for high-bandwidth connections simultaneously.
Cable jacket colors are orange for OM1/OM2, aqua for OM3/OM4 and lime green for OM5. Cable construction will generally vary, providing furcated and multicore fibers for specialized installation needs.
| Connector Type | Ferrule Size | Typical Insertion Loss | Application Features | Cost |
| LC | 1.25 mm | 0.25-0.5 dB | High density, cost-effective | Moderate |
| SC | 2.5 mm | 0.25-0.5 dB | Mainstream, reliable | Low |
| ST | 2.5 mm | 0.25-0.5 dB | Legacy, field fit | Low |
| MPO | Multi-fiber | 0.35 dB | High bandwidth, data centers | High |
Practical Guidance: Selecting the Appropriate Multimode Fiber Optic Cable
The choice of fiber will depend on distance, bandwidth, budget, and any potential future use. OM1/OM2 fiber will be appropriate for legacy systems or cost-sensitive networks, while OM3/OM4 supports data centers with multimode cables or higher bandwidths. OM5 is the best solution for multimode cables with wideband WDM and future use. If someone is using fiber in their network, they should follow proper installation techniques and testing methodologies to preserve the desired performance in a network.
Frequently Asked Questions
What is multimode fiber?
Fiber capable of transmitting multiple light modes over short- to mid-range distances.
What is the difference from OM1 to OM5?
The difference between OM1 through OM5 is the core size, bandwidth limitations, distance and optical source used.
What are the max distances?
OM1-spec multimode fiber can reach a maximum distance of 275m while transmitting a single 1Gbps data stream. OM5 can transmit 150m+, while transmitting 100Gbps data streams.
What jacket color corresponds with each fiber?
OM1 and OM2 fiber are orange; OM3 and OM4 fiber are aqua; OM5 is lime green.
Are the fiber cables compatible?
OM4 multimode fiber is backward compatible with OM3.
What is bandwidth?
Bandwidth refers to the overall capacity of a transmission medium over a given distance.
How do I choose a fiber?
There are a variety of factors to take into consideration when choosing any fiber: distance, speed of data, budget, and scalability.
Conclusion
Understanding the use of multimode fiber optic cables and the types of fibers: OM1 through OM5 offers different performance characteristics and best usage applications. The use of OM5 multimode fibers will play a critical role in wideband networks in the future. Fiber optic cable charts (and the system designer, of course) will help with the optimal decision regarding the type of cable that will provide the best outcome.
More importantly, a proper fiber optic cabling installation and testing process will also contribute to the reliability and availability of a network.
Related Article:
Single Mode vs Multimode Fiber Cable: Guide to Fiber Optic Cable Types and Applications