Quotient from velocity of light in vacuum and phase
velocity

Propagation velocity of a flat (monochromatic) wave

Component that absorbs light energy and produces
a photoelectric current

Quantum of an electromagnetic field, ‘light particle’

Special two-dimensional shape of a photonic crystal.
Fiber with a plurality of microscopic holes parallel
to the optical axis of the fiber. The mode guidance
is achieved by deliberately installing ‘defects’.

Periodic structures with dimensions in the order
of magnitude of the wavelength of light or below.
Area of research of (nano-)optics, where considerable
impetus is expected for the development of future,
signal-processing functional elements.

Short section of a fiber optic cable having a connector
for coupling optical components to the transmission
link.

Receiver diode with predominant absorption
in a space-charge region (i-zone) within its pn junction.
Such a diode has a high defective quantum efficiency,
but unlike avalanche photodiodes no internal
current amplification.

Waveguide structure that is created on
or at the surface of substrates.

Property of a transversal wave of retaining
certain oscillating states. Polarisation is proof
of the transversal nature of an electromagnetic wave.

Dispersion arising from delay differences between the
two modes which are oscillating orthogonally to each
other. Polarisation mode dispersion only occurs in singlemode
fibers. It only has any significance at high bit
rates and with a drastic reduction in the chromatic
dispersion.

The difference (in dB) between maximum and minimum
attenuation values as the result of a change
in the state of polarisation of the light propagating
through the component.

Refractive index profile whose radial characteristic
is described as a power of the radius.

Optical amplifier that is used directly upstream
of the receiver.

Optischer Verstärker, der direkt vor dem Empfänger
eingesetzt wird.

Glass rod comprising core glass and cladding glass
which can be drawn to form a fiber.

Is the coating applied directly to the cladding surface
when manufacturing the optical fiber. It may comprise
a number of layers. This preserves the integrity
of the surface.

Is the coating applied directly to the cladding surface
when manufacturing the optical fiber. It may comprise
a number of layers. This preserves the integrity
of the surface.

System for aligning fibers in splicers with the aid
of an image of the fiber structure on a CCD line.

Dispersion arising from an unsatisfactory adaptation
of the profile exponent of a parabolic index fiber
to the spectral properties of the optical transmitter.

Parameter with which the shape of the profile
is defined for power-law index profiles. Particularly
important profile exponents in practice are g ≈ 2
(parabolic index fiber) and g ➔ ∞ (step index fiber).