Comparison Between OM1, OM2, OM3 and OM4

Multimode fibers are identified by the OM (optical mode) designation as outlined in the ISO/IEC 11801 standard. Multimode fiber cables can be found in OM1, OM2, OM3 and OM4 types. Each type has different properties. This post will reveal a comparison between the four different multimode fibers.

development of multimode fibers

Parameters & Specification

The original multimode fiber (MMF) standard ANSI/TIA-492AAAA5 for OM1 fiber, was released in 1989 to support Fast Ethernet 100BASE-FX and 1000BASE-SX Ethernet. It’s a kind of multimode fiber with 200/500 MHz.km overfilled launch (OFL) bandwidth at 850/1300nm.

The ANSI/TIA-492AAAB standard for OM2 fiber was released in 1998, with an improved modal bandwidth to support higher data transmission, such as 1 Gbps VCSEL with longer reach. It’s a kind of multimode fiber with 500/500 MHz.km OFL bandwidth at 850/1300nm.

To meet growing bandwidth requirements, laser-optimized multimode fiber (LOMMF) standards OM3 and OM4 fiber cable were developed in 2002 and 2009 respectively. OM3 cable refers to laser-optimized 50µm fiber having 2000 MHz.km effective modal bandwidth (EMB, also known as laser bandwidth) designed for 10 Gb/s transmission. OM4 cable means laser-optimized 50µm fiber having 4700 MHz.km EMB bandwidth designed for 10 Gb/s, 40 Gb/s, and 100 Gb/s transmission.

specification

Design & Application

OM1 cable typically comes with an orange jacket and has a core size of 62.5 micrometers (µm). It can support 100 Megabit Ethernet at lengths up 33 meters. It is most commonly used for 100 Megabit Ethernet applications.

OM2 fiber also has a suggested jacket color of orange. Its core size is 50µm, smaller than OM1 fiber. It supports 1 Gigabit Ethernet at lengths up to 82 meters but is more commonly used for 1 Gigabit Ethernet applications. Both OM1 and OM2 work well with LED based equipment that can send hundreds of modes of light down the cable. And for yeas they have been widely deployed in the interior of the building.

OM3 multimode fiber has a suggested jacket color of aqua. Like OM2, its core size is 50µm, but the cable is optimized for laser based equipment that uses fewer modes of light. As a result of this optimization, it is capable of running 10 Gigabit Ethernet at lengths up to 300 meters. Besides, OM3 cable is able to support 40 Gigabit and 100 Gigabit Ethernet up to 100 meters if a MPO connector is utilized. 10 Gigabit Ethernet is its most common use.

OM4 fiber also has a suggested jacket color of aqua. It is a further improvement to OM3. It also uses a 50µm core but it supports 10 Gigabit Ethernet at lengths up 550 meters and it supports 100 Gigabit Ethernet at lengths up to 150 meters utilizing a MPO connector. Generally, OM3 and OM4 fiber optic cables are typically used in the data center wiring environment to support the transmission of 10G, even the 40/100G high speed Ethernet network.

design

Limitations

OM1 fiber can cause excessive signal loss, even at a short reach when mating with newer MMF types (core diameter 50µm). Both OM1 and OM2 can only support very limited reach for links above 1G, and can no longer support system speed upgrades. In today’s data center, OM1 and OM2 MMF types aren’t recommended for new greenfield installation.

OM1 and OM2 have higher fiber cable attenuation (3.5 dB/km) compared to OM3 and OM4 (3.0dB/km); therefore, the appropriate link budget may not be met.

Currently, OM3 and OM4 are the most popular MMF types deployed in modern data centers. OM3 MMF can support the latest Ethernet and Fibre Channel applications with reduced reach; however, cautions must be taken when mating legacy OM3 MMF with new bend-insensitive MMF (BI-MMF). The slight difference in fiber geometry could cause additional loss, negatively impacting cable performance.

OM4 BI-MMF is recommended for new fiber installation or fiber upgrade and replacement projects because the latest application standards are developed based on OM4 specifications.

Summary

In a nutshell, Multi-mode fiber is typically cost effective for inside buildings or corporate campuses where the lengths don’t exceed a few hundred meters. When it comes to network speed upgrades, our recommendation is that you replace old OM1/OM2 or legacy OM3 with high-quality OM4 BI-MMF cabling to prevent light from escaping and causing bend-induced attenuation. This leads to better performance, higher bandwidth capabilities and improved optical performance. FS.COM will always offer a best cabling solution for you. For more details, please contact sale@fs.com.

Differences Between Fiber Patch Cords and Fiber Pigtails

Fiber patch cords and fiber pigtails are two kinds of commonly used network connectivity components in fiber optic network. They share many common characteristics, and in some ways there are also some differences. To understand the similarities and differences will help you make the best choice for your application. This post will give you a better understanding of the differences between fiber optic pigtails and patch cords.

Fiber Patch Cord

A patch cord is a length of cable with connectors on each end that is used to connect end devices to power sources. Patch cords are made from either single or multi-fiber cables and connected at each end with fiber cable connectors. Sometimes fiber patch cables are called jumpers, especially if they are simplex or duplex. The connectors are selected to mate with the interfacing equipment or cable connectors. The fiber can be either tight or loose buffered and can be made of various diameters (1.2 mm to 3.0 mm are common).

fiber patch cable

Fiber Pigtails

Pigtails bridge a critical junction in the fiber-optic network. The fiber pigtail is a fiber cable with a factory installed connector on one end and an unterminated fiber on the other, so that the connector side can be linked to the equipment and the other side can be melted with optical cable fibers or stripped and fusion spliced to a single fiber of a multi-fiber trunk.

fiber pigtail

Structural Difference Between Fiber Patch Cords and Fiber Pigtails

Fiber optic patch cables and fiber optic pigtails structurally have much in common. They are both available in single mode and multi-mode, and they can be made into simplex and duplex. Besides, both fiber patch cords and pigtails can terminate with many kinds of fiber optic connectors, including FC, SC, ST, LC, MTRJ, MPO, MU, SMA, FDDI, E2000, DIN4, and D4.

FC, SC, ST, LC

The major physical difference between fiber patch cord and pigtail is that fiber patch cord is a fixed length piece of cable with fiber connectors on each end while fiber pigtail has fiber connectors on only one end of the cable. Fiber optic patch cords can be cut into shorter lengths to make two pigtails.

Applications of Fiber Patch Cords and Fiber Pigtails

Fiber optic patch cords and pigtail fibers provide interconnect and cross-connect of applications over installations in entrance facilities, telecommunications rooms, and data centers. They are available in OM4, OM3, OM2, OM1, or OS1/OS2 fiber types, and can meet the demands of Gigabit Ethernet, 10 Gigabit Ethernet and high speed Fibre Channel. However, they have their respective application areas, too.

Fiber patch cords are commonly used to connect ports on fiber distribution frames (FDFs). They support network applications in main, horizontal and equipment distribution areas and are available in optical fiber riser cable (OFNR), and low smoke zero halogen (LSZH) rated jacket materials to comply with local cabling ordinances. They also support high speed (10/40 Gbs) telecommunications. Fiber optic patch cords can also be used in many areas, such as integrated optics, laser detection and display, and materials processing, etc.

Fiber optic pigtails support fusion splice field termination applications. They should be installed in the protected and splice needed place, so they are usually used with optical fiber management devices like optical distribution frame (ODF), splice closures and optical fiber distribution boxes. Applications of fiber pigtails are found everywhere, but most commonly in optical assemblages or optical components. For example, there are waterproof fiber optic pigtails with thick polyethylene (PE) jacket and large diameter used for outdoor applications.

Conclusion

Although patch cords and fiber pigtails look very similar, they still have some differences in structure and application. A better understanding of the differences can help you choose the right one in your application. If you are still confused about them, feel free to contact fs.com. All types of fiber optic patch cables and fiber pigtails can be found at FS.COM, which offer low insertion losses and excellent repeatability. And they can be manufactured to custom length.

Things You Should Know About Patch Cords

Definition

A patch cord or patch cable is a length of cable with connectors on each end that is used to connect end devices to power sources. These cables are mainly used to connect one electronic device to another. Inside the patch cord is glass core used for transmitting light. Outside the core is wrapped up glass envelope with lower refractive index so as to keep the fiber inside the core. The outer layer is covered with a thin plastic coat for protection.

Classification & Features

There are many types of patch cords, such as FC patch cords, LC patch cords, SC patch cords, and ST patch cords. Then what are the differences and features between them? Take FS.COM fiber patch cable as an example.

1. FC fiber patch cable. The external of it is strengthened by metal sleeve and ruggedized by screw buckle. It is usually used on ODF. Generally, telecommunications network would adopt FC connector, screwing a nut onto a adapter.

Pro: solidity, dust proof    Con: long time for installation

FC

2. SC fiber patch cable. It is a connector which has a rectangular enclosure, used for connecting GBIC optical modules. It is ruggedized through the method of plug pin latch without rotating. It’s mostly used in switches and routers. SC connectors are commonly used in general network.

Pro: direct plugging in/out, easy operation    Con: easy to fall out

SC

3. ST fiber patch cable. It’s commonly used in fiber distribution frame with its enclosure round, and it’s ruggedized with the help of turnbuckle. ST connectors are also commonly used in general network.

Pro: fixation    Con: brittleness

ST

4. LC fiber patch cable. It’s a connector connecting SFP optical modules. It adopts modular jack (RJ) latch method, which is convenient to operate. It’s often used in routers.

Pro: bend insensitive, efficient installation    Con: easily detached

LC

Application

Ethernet patch cable find many uses in a wide variety of industries and applications. Some uses of patch cords include: FTTH, LAN, fiber optic sensor, optical fiber communication system, fiber optic connection transmission equipment, national defense, telecommunication network, computer optical fiber network and optical test equipment, etc.

Using Tips

If you have no idea about how to install patch cords, then you should read the instructions and using tips before installation.

1. Before use, you should clean the ceramic ferrule and the core end face of patch cable up with alcohol and absorbent cotton.

2. While using, the minimum bending radius of fiber optic shouldn’t exceed 150mm.

3. Protect the core and the end face of the core from bruising and pollution. Put on a dust cap immediately after disassembly.

4. When laser signals are being transmitted, do not look directly at the optical fiber.

5. Patch cords should be replaced in time after man made or non-resistant damages.

6. Please read the instruction manual carefully before installing, and debug under the guidance of the engineer of manufacturers or dealers.

7. When optical network or system malfunctions, troubleshooting methodology could be adopted to test. A continuity testing could be put ahead when you do the test or exclude the malfunction of patch cords. In general, you can use visible laser light to judge the whole optical fibre link or use optical fiber insertion loss return instrument to test all the indexes. The index will tell whether the patch cord is normal or not.

Summary

This post gives a brief introduction to patch cables, and lists some products from FS.COM to throw light upon the classification and features of patch cables. Also it tells about the application and using tips of patch cables. I hope it may be helpful to you if you are a green hand fiber optic technician. If you would like to know more or would like assistance in choosing the right cabling infrastructure, welcome to visit our website www.fs.com for more detailed information. FS will provide more choices and better services for our clients.