A fiber-optic patch cord is a fiber optic cable capped at either end with connectors that allow it to be rapidly and conveniently connected to CATV, an optical switch or other telecommiunication equipment. Its thick layer of protection is used to connect the optical transmitter, receiver, and the terminal box
Fiber optic patch cords are characterized by
Low insertion loss
High return loss
Good repeatability
Good interchange
Excellent environmental adaptability
Construction
A fiber optic patch cord is constructed from a core with a high refractive index, surrounded by a coating with a low refractive index, that is strengthened by aramid yarns and surrounded by a protective jacket. Transparency of the core permits transmission of optic signals with little loss over great distances. The coating’s low refractive index reflects light back into the core, minimizing signal loss. The protective aramid yarns and outer jacket minimizes physical damage to the core and coating
Transmission medium
Single-mode fiber is generally yellow, with a blue connector, and a longer transmission distance. Multi-mode fiber is generally orange or grey, with a cream or black connector, and a shorter transmission distance
Connector construction
Connector design standards include FC, SC, ST, LC, MTRJ, MPO, MU, SMA, FDDI, E2000, DIN4, and D4. Cables are classified by the connectors on either end of the cable; some of the most common cable configurations include FC-FC, FC-SC, FC-LC, FC-ST, SC-SC, and SC-ST
Armored fiber patch cord
Armored fiber optic patch cord uses a flexible stainless steel tube inside the outer jacket as the armor to protect the fiber glass inside. It retains all the features of standard patch cord, but is much stronger. It will not get damaged even if stepped by an adult and they are rodent-resistant
Mode-conditioning patch cord
A mode-conditioning patch cord is required where Gigabit 1000 Base-LX routers and switches are installed into existing multimode cable plants. The transceiver modules launch only single-mode 1300 nm signals but the existing network is built with multimode cables
A single-mode laser launch into the center of a multimode fiber can generate multiple signals that confuse the receiver at the other end of the fiber. These multiple signals, caused by Differential Mode Delay (DMD) effects, limit the system distance lengths for operating Gigabit Ethernet. A mode-conditioning patch cord eliminates these multiple signals by aligning the single-mode launch away from the center of a multimode fiber core. This offset launch creates a transmitted signal that is similar to a typical multimode light-emitting diode (LED) launches