Category Archives: Bulk Fiber Cables

What Is an Optical Cable and Why Do We Need It?

Fiber optic communication technology has emerged for a long time. It makes data transmission faster and faster, and itself has gradually become indispensable. Our business and daily life have benefited a lot from this technology. But how much do you know about fiber optic technology? What is an optical cable? What is an optical cable used for and why use optical cable? All tells in this post.

What Is an Optical Cable?

Optical cable, also known as fiber optic cable, is a kind of cable that has strands of glass or plastic fibers inside individual protective covers. The optical cable is used for digital data signals transferring in the form of light. The fiber optic cable distance can be up to hundreds of miles. In addition, optical cable has higher throughput rates than those achievable via electrical communication cables. As for fiber optic cable types, there are two common types: single mode fiber and multimode fiber.

No matter single mode fiber or multimode fiber, the basic fiber optic cable structure contains three parts: the core, cladding, and outer jacket. The cylindrical transparent core is very thin and flexible. The cladding is transparent, too. While the material of the cladding is different from that of the core. Finally, the outer jacket (or coating), whose main function is purely to protect the core and the cladding, is often made up of a strong and flexible material.

what is an optical cable structure

Figure: Fiber Optic Cable Structure

Why Use Optical Cable?

Getting to know what is an optical cable and what is an optical cable used for in the previous text, here comes to another point – why use optical cable. The fiber optic cable advantages are listed below.

  • Long Distance – As stated above, fiber optic cable distance can be up to hundred of miles. Generally, single mode fiber distance is about 200 km while multimode fiber distance is 2 km.
  • Fast Speed – Fiber optic cable speed varies on single mode fiber and multimode fiber. Single mode fiber speed is among 100 Mbit/s, 1 Gbit/s, 10 Gbit/s, 40 Gbit/s and 100 Gbit/s, but it usually runs at 40 Gbps or 100 Gbps for the long-haul data transmission. Multimode fiber speed is typically among 100 Mbit/s, 1 Gbit/s and 10 Gbit/s, but it also can support 40 Gbps or 100 Gbps for the relative short distance.
  • Overall Low Cost – With fiber network being common, optical cable price is not as high as before. You can choose single mode fiber patch cables and multimode fiber patch cables among various fiber optic cable manufacturers. FS.COM is a nice place to buy optical cables whose optical cable price is very low compared with other cable suppliers. And most of the fiber cables are in stock and ready for shipping.


After reading this post, you should be able to get a general picture of what is an optical cable and why do we need it. There is no doubt that the future of optical communication is expected, and optical communication will bring us more opportunities and convenience. If you have not deployed optical cable network, now is the time to begin. Please remember: buying optical cables from reliable fiber optic cable manufacturer would save you lots of money and maintenance time.

Cable Jacket Rating: Something You Need to Know

As the first defense line against the surrounding environment, the cable jacket prevents the core of fiber optic cable from water, flame, chemistry, etc. Meanwhile, the outermost layer keeps inert to gases and liquids that may be exposed during its service life. Besides, the cable jacket provides a smooth, low friction surface. The jacket must be made of a material that can keep the cable flexibility and maintainability at all temperatures during its service life. Today our topic is the cable jacket rating of fiber optic cable.

What Is Cable Jacket?

The optical fiber cable is composed of the inner core, cladding, coating, strength member and the outer cable jacket. The core made of plastic or glass is a physical medium used for optical signal transmission. Because bare fibers are easily broken, outer cable jacket is required to protect optical fibers. Just like mentioned above, the cable jacket is the first line of moisture, mechanical, flame and chemical protection for cables. If there is no jacket, fiber optic cable is likely to be damaged during and after installation. Common jacket materials are PE (Polyethylene), PVC (Polyvinyl Chloride) and LSZH (Low Smoke Zero Halogen).

cable jacket: fiber cable structure

Fiber Cable Structure

Cable Jacket Rating of Fiber Optic Cable

In general, the NEC (National Electrical Code) provides eight grades of fire resistance for non-conductive and conductive cables. All indoor cables must be marked and installed for the intended purpose: plenums, risers, and general purpose areas.

  • Plenums: A plenum area is is used for air flow or air distribution system (ceiling and elevated floor) building space.
  • Risers: A riser area is a floor opening, shaft or pipe vertically passing through one or more floors.
  • General purpose areas: The general area refers to all other areas on the same floor without pressure ventilation systems or risers.

Cable jacket rating is important. If the cables do not have these ratings, they cannot be installed on walls or ceilings. Here we will introduce the most common cable jacket ratings that you will encounter.

  • CL/CM/CMG: These cable jackets are applicable to all common situations. Specifically, CL cables are used for audio and video applications, and CM/CMG for communication applications, such as Ethernet. They are all tested through the so-called “vertical tray flame test”, which means they usually won’t spread the flame more than eight feet. You can install these rated cables on walls or ceilings without worrying about risers and plenums at home.
  • CMR: The CMR rating means that the cables can be used in the risers of commercial buildings because they limit flame spread better than the cables in the CL/CM series. In addition to plenums, they can be installed anywhere.
  • CMP: “P” clearly represents the plenum, so in addition to the places where CM and CMR cables can operate, this communication cable can also be used for plenums. The jacket is made of the material that retards the spread of flame. It does not emit a large amount of smoke or poisonous gas when it burns.


These are the common ratings of fiber optic cable jacket. We should follow these cable jacket ratings in the NEC guidelines to minimize the risk of impact, fire and toxic smoke in each area, thus preventing fire. Besides, fiber optic cable plays an important role in the field of communication. You can visit to find fiber cables that can meet your needs, such as single mode fiber optic cable, multimode fiber optic cable, and fiber patch cord. I hope you can get your own cable.