| Absorption |
That
portion of optical attenuation in optical fiber
resulting from the conversion of optical power to
heat. Caused by impurities in the fiber such as
hydroxyl ions. |
| Acceptance
Angle |
The
half-angle of the cone within which incident light
is totally internally reflected by the fiber core.
It is equal to sin-1(NA). |
| APC |
Abbreviation
for angle polished connector. An 5°-15°
angle on the connector tip for the minimum possible
back reflection. |
| Armor |
A
protective layer, usually metal, wrapped around
a cable. |
| Asynchronous
Transfer Mode (ATM) |
A transmission
standard widely used by the telecom industry. A
digital transmission switching format with cells
containing 5 bytes of header information followed
by 48 data bytes. Part of the B-ISDN standard. |
| Attenuation
|
Loss
of signal power between points. In optical cables,
attenuation is a ratio of input power vs. output
power, measured in decibels per unit length, usually
dB/km. |
| Attenuation
Coefficient |
A factor
expressing optical power loss per unit of length,
expressed in dB/Km. |
| Avalanche
Photodiode (APD) |
A photodiode
that exhibits internal amplification of photocurrent
through avalanche multiplication of carriers in
the junction region. |
| Average
Power |
The
average level of power in a signal that varies with
time. |
