A band of wavelengths where silica fiber attenuation dips between absorption peaks. Multimode systems work in the 850 and 1300 nm windows; singlemode uses 1310 and 1550 nm, with 1625 nm used for monitoring. The telecom bands are also named O-band (1260 to 1360 nm), C-band (1530 to 1565 nm) and L-band (1565 to 1625 nm).
Shoot it at both windows, 1310 and 1550, so we can see if that loss at the handhole is a bend.
Also heard as
- transmission window
Do not mix it up with
- Lambda: A lambda is one specific wavelength channel; a window is a whole low-loss band that can hold many lambdas.
Related terms
Attenuation coefficient
Fiber loss per unit length, in dB/km, which sets how much a given length of glass will lose.
Lambda
A single wavelength channel on a fiber, named after the Greek letter used for wavelength.
Macrobend
A bend in a fiber tight enough to see, which lets light escape the core and causes loss.
WDM
Wavelength Division Multiplexing: sending several signals on different wavelengths over the same fiber.