Glossary

In fiber optics, the amount of optical power required by a particular receiver in order to transmit a signal with few errors. Can be considered a measure of the overall quality of receiver. The more sensitive the receiver, the better its quality.

In fiber optics, the amount of optical power required by a particular receiver in order to transmit a signal with few errors. Can be considered a measure of the overall quality of receiver. The more sensitive the receiver, the better its quality.

The part of a fiber-optic receiver that accepts a connector and aligns the ferrule for proper optical transmission.

A percentage that represents the amount of light that is reflected back along the path of transmission from the coupling region, the connector, or a terminated fiber.

(1) A return of electromagnetic energy that occurs at an impedance mismatch in a transmission line, such as a LAN cable. See also return loss. (2) The immediate and opposite change in direction that happens to a light beam when it strikes a reflective surface. Reflection causes several spectral problems, including high optical distortion and enhanced intensity noise.

The bending of a beam of light as it enters a medium of different density. Refraction occurs as the velocity of the light changes between materials of two different refractive indexes.

The change in refractive index with respect to the distance from the axis of an optical fiber.

A graphical description of the relationship between the refractive indexes of the core and the cladding in an optical fiber.

A receiver-transmitter pair that detects a weak signal, cleans it up, then sends the regenerated signal through another length of fiber.

A professional accreditation granted by BICSI (the Building Industry Consulting Service International). RCDDs have demonstrated a superior level of knowledge of the telecommunications wiring industry and associated disciplines.

An electrical box that is designed to clamp to the wallboard, as opposed to a

(1) A device that receives, amplifies (and reshapes), and retransmits a signal. It is used to overcome attenuation by boosting signal levels, thus extending the distance over which a signal can be transmitted. Repeaters can physically extend the distance of a LAN or connect two LAN segments.

In DC (direct current) circuits, the opposition a material offers to current flow, measured in ohms. In AC (alternating current) circuits, resistance is the real component of impedance and may be higher than the value measured at DC.

A measure of the inequality of the resistance of the two conductors of a transmission line.

(1) The ratio of a detector