Hybrid Fiber Coax (HFC):A cable construction that includes both optical fiber and copper components as transmission media.

HFC Network:A telecommunications network consisting of both fiber optic and copper components,as in FTTC.

IEEE:Abbreviation for Institute of Electrical and Electronics Engineers.A professional association that contributes to voluntary standards within these industries.

Index of Refraction:The ratio of the velocity of light in free space to the velocity of light in a fiber.

InGaAsP:Abbreviation for Indium Gallium Arsenide Phosphide.Used in high performance detectors.

Insertion Loss:Loss resulting from inserting a component (connector,splice,etc.) into a fiber path.

Interferometer:An instrument used to measure the endface geometry of a fiber optic connector for critical parameters including apex offset,radius of curvature,and fiber height.

Intrinsic Loss:Loss in spliced fibers due to differences in the fibers being spliced.