Hinter den zu messenden Lichtwellenleiter nachgeschalteter
Lichtwellenleiter.

Noise of the optical receiver caused by interference
of delayed signals through multiple reflections at
points along the length of the fiber.

Ratio of the signal-to-noise ratio at the input
to the signal-to-noise ratio at the output of the optical
amplifier. As each amplifier always adds its own
noise, the noise figure is always >1. It is a power ratio
and is given in decibels. At best, the noise figure
is equal to 3 dB.

Method for modulating amplitudes in which
the on and off levels are maintained for an entire
bit interval.

Change in the amplification as a function of the
wavelength. The slope of the amplification profile
is expressed in dB/nm.

Fiber with a small, non-zero coefficient of chromatic
dispersion in the wavelength range of the 3rd optical
window. This fiber is used in multichannel (DWDM)
systems and is suitable for reducing the effect of fourwave
mixing.

The dielectric material properties change with a high
energy density in the fiber core (generally speaking,
in a strong electromagnetic field). The effects, which
are weak per se, increase as a result of the generally
long sections that the optical signals travel in fiber.

Collective term for nonlinear optical effects:
FWM, SBS, SPM, SRS and XPM.

Dimensionsloser Parameter, der vom Kernradius, der
numerischen Apertur und der Wellenlänge des Lichts
abhängt. Durch die normierte Frequenz wird die
Anzahl der geführten Moden festgelegt.

The sine of the acceptance angle of a fiber. The numerical
aperture is dependent on the refractive
index of the core and of the cladding. An important
parameter for characterising a fiber.