Fiber Optic Patch Cable - (color coding)

Fiber optic patch cable, is also known as fiber optic jumper or fiber optic patch cord which is composed of a fiber optic cable terminated with different connectors on the ends.

 

Fiber optic patch cable is used to cross-connect installed cables and connect communications equipment to the cable plant.It is a very important component of the network.

 

In general, fiber optic patch cables are classified by fiber cable mode or cable structure, by connector construction and by construction of the connector's inserted core cover.

 

Fiber Cable Mode & Structure

 

According to the fiber cable mode, fiber optic patch cables are divided into two common types - Singlemode fiber patch cable and Multimode fiber patch cable. Singlemode fiber patch cables use 9/125 micron bulk single mode fiber cable and single mode fiber optic connectors at both ends. Singlemode fiber patch cable is generally yellow with a blue connector and a longer transmission distance. Multimode fiber patch cables use 62.5/125 micron or 50/125 micron bulk multimode fiber cable and terminated with multimode fiber optic connectors at both ends. It is usually orange or grey, with a cream or black connector, and a shorter transmission distance. According to the fiber optic cable structure, fiber optic patch cables include simplex fiber optic patch cable and duplex fiber optic patch cable. The former has one fiber and one connector on each end while the latter has two fibers and two connectors on each end. Each fiber is marked “A” or “B” or different colored connector boots are used to mark polarity.

 

Connector Construction

 

Connector design standards include FC, SC, ST, LC, MTRJ, MPO, MU, SMA, FDDI, E2000, DIN4, and D4. Fiber optic patch cables are classified by the connectors on either end of themselves. Some of the most common patch cable configurations include FC-FC, FC-SC, FC-LC, FC-ST, ST-LC, SC-SC, and SC-ST.

 

Construction of the Connector's Inserted Core Cover

 

Fiber optic connectors are designed and polished to different shapes to minimize back reflection. This is particularly important in single mode applications. Typical back reflection grades are -30dB, -40dB, -50dB and -60dB. The connector's inserted core cover conforms to APC (Typical back reflection <-60dB), UPC (Typical back reflection <-50dB), or PC (Typical back reflection <-40dB) configuration.

 

The buffer or jacket on patchcords is often color-coded to indicate the type of fiber used. In addition, color-coding of connectors for different fiber standards make it easy to avoid confusion.

 

Fiber Color Codes

 

Similar to the color coding designations of copper cabling, optical fiber has a color code designation for strands of fiber within the larger cable, as well as the cable's jacket. These color codes are set by the EIA/TIA-598 standards guide identification for fiber and fiber related units that determines which color codes are used in which applications. The colors don't only apply for the application though, they also are meant to be of use in determining a cables properties. The differences in colors are based upon different levels of OM and OS fiber (Optical Multimode & Optical Singlemode).

 

Optical fiber cable is separated into strands, which are the individual fibers within the larger piece of cabling. Up to 24 individual strands can be manufactured loosely, and after that point they are usually sectioned into tubes containing 12 each. Each tube containing 12 strands is then given a color.

 

Connector Color Codes

 

Since the earliest days of fiber optics, orange, black or gray was multimode and yellow singlemode. However, the advent of metallic connectors like the FC and ST made connector color coding difficult, so colored strain relief boots were often used.