Back Reflection (Fiber Optic):

A measure of the percentage of power reflected back by a discontinuity in a fiber optic line. It is expressed in dB.


The frequency range over which the connector or device can operate without degradation of performance. Also the information carrying capacity of digital systems.

Base Metal:

The metal from which the connector, contact or other metal accessory is made and on which one or more metals or coatings may be deposited.

Bend Radius:

The maximum amount fiber or cable that can be bent without causing damage. Also called minimum safe bending radius.


The covering formed from textile yarn. Braids provide mechanical and thermal protection to plastic insulation, separate cable segments in multi-conductor cables and act as components in flame retardant cables. See also Shield.

Breakdown Voltage:

The voltage at which the insulation between two conductors will break down.

Bundle (Fiber Optic):

A number of fibers grouped together (rigid or flexible), usually carrying a common signal (or an image, or a conduit for transfer of light power).