| Backreflection
(BR) |
In
cases where light is launched into an optical fiber,
backreflection refers to the light that is returned
to the launch point. |
| Backscattering |
The
return of a portion of scattered light to the input
end of a fiber; the scattering of light in the direction
opposite to its original propagation. |
| Backbone
|
A high-speed
transmission system used to connect relatively distant
points. Backbone networks can be used to join autonomous
networks within buildings or between different buildings |
| Bel
(B) |
The
logarithm to the base 10 of a power ratio, expressed
as B = log10(P1/P2), where P1 and P2 are distinct
powers. The decibel, equal to one-tenth bel, is
a more commonly used unit. |
| Bending
Loss |
Attenuation
caused by high-order modes radiating from the outside
of a fiber optic waveguide which occur when the
fiber is bent around a small radius. See also macrobending,
microbending. |
| Bandwidth
|
The
information carrying capacity of a fiber. The bandwidth
for a given wavelength is the lowest frequency at
which optical power has decreased by 3 dB and is
expressed in MHzokm. |
| Bend
Radius |
The
radius of curvature that an optical fiber cable
can bend without causing harmful effects on the
optical or mechanical performance of the cable. |
| BER
(Bit Error Rate) |
The
fraction of bits transmitted that are received incorrectly. |
Bidirectional
|
Operating
in both directions. Bidirectional couplers operate
the same way regardless of the direction light passes
through them. Bidirectional transmission sends signals
in both directions, sometimes through the same fiber. |
| Birefringent |
Having
a refractive index that differs for light of different
polarizations. |
| Broadband |
A method
of communication where the signal is transmitted
by being impressed on a high-frequency carrier. |
| Buffer |
In
optical fiber, a protective coating applied directly
to the fiber. 2) A routine or storage used to compensate
for a difference in rate of flow of data, or time
of occurrence of events, when transferring data
from one device to another. |
