HCS fibers are step index fibers with large silica core. They are used in applications demanding high mechanical performances. They are the best choice for industrial data links and factory automation, trains and military applications. The large core references (up to 1500 μm) will be used for power laser transmission.
When people discuss fiber optics, they usually refer to singlemode or graded-index optical fiber.These silica fiber types are very appropriate for high-speed data communication over long distances. But step-index silica fibers are the preferred choice for low cost, short distance datalinks.Their large core size permits the use of low cost transmitter/receiver technology.The fiber’s high tensile strength allows easy field terminations and makes possible the use of low cost devices and connectors.
The most commonly used fiber is HCS (Hard Clad Silica). HCS fiber provides an excellent balance of performance characteristics.Their large core diameter and high numerical aperture (0,37) provide effiscient coupling to sources. For example considering the size of a 200 μm core HCS fiber and it’s 0.37 N.A. it is possible to couple ten times more power from an LED than with a 62.5/125 fiber and about five time more than with a 100/140 fiber.