Glossary

A

Attenuation

(de: Dämpfung)
Describes the reduction of optical signal strength at a component or fiber; measured in dB.
a = 10 · log(Pin / Pout)

Attenuation Coefficient

(de: Dämpfungsbelag)
Describes the attenuation of an optical fiber, with respect to fiber length; measured in decibels per kilometer (dB/km).
α = 10 · log( Pin / Pout) / lfiber
B

Band Gap

(de: Bandlücke)
Gap between valence and conduction band in light-emitting semiconductors. The emitted wavelength λ can be approximated from the band gap Eg

λ = 1.24 µm / ( Eg [eV] )

Bandwidth (optical)

(de: Bandbreite (optisch))

Bending Loss

(de: Biegeverluste)
Bending Loss Loss at bendings occurs in all multimode fibers. For POF, optical attenuation is typically defined for ten bendings of 90° each or for one single 360°-bend.
The figure shows an example for a 1 mm SI-POF (bent at 90°).