What are sidelight fibers?

Sidelight fibers are optical waveguiding fibers that are manufactured in such a way that the light guided in their core is not only transmitted to the fiber endface, but also emitted at the side.

Sidelight fibers are a concept for avoiding direct light radiation from the light source to the human eye. Often the direct view into a very bright shining source, such as an LED chip, is uncomfortable and dazzling. Although diffuser panels in the lamp construction can partly avoid the unpleasant light effect, most of the time these lamps are also much brighter than one would wish for ambient lighting in an environment intended for a relaxed stay.

Comparsion between sidelight and endface POF
Comparsion between sidelight and endface POF

The picture above depicts a 3mm endlight fiber (lower) and a sidelight fiber (upper). Both are supplied with the same light power. The light at the end of the sidelight fiber is less bright, because parts of the light are emitted to the ambient.

Application for sidelight fibers

Sidelight fiber systems generate light by lateral emission from the optical waveguide.

Typically sidelight fibers are made of a plastic material and are therefore called POF (Polymer Optical Fibres) sidelight fibers. Ideally, the light coupled into the frontal endface is emitted over the entire lateral surface.

In the ideal case the light coupled into the front surface is emitted evenly over the entire jacket surface. A very bright light source concentrated on a single point is radiated over a large area and thus perceived as pleasant ambient light.