valgusjuhte

Valgusjuhte are structures or components that guide light along a defined path while minimizing loss. The term is used primarily in Estonian-language texts to refer to optical waveguides, including optical fibers and planar, chip-scale waveguides. The guiding principle is total internal reflection: light is confined in a core with higher refractive index surrounded by a cladding with lower index.

They are typically made from silica glass or polymers, with core and cladding materials selected for the desired wavelength range. Variants include cylindrical optical fibers, planar waveguides for integrated photonic circuits, and light pipes used for illumination. Fabrication methods include fiber drawing from a preform, chemical vapor deposition to build thin-film layers for planar waveguides, and extrusion for polymer fibers.

In telecommunications, valgusjuhte carry data over long distances; in medicine, they serve as endoscopes and illumination channels; in consumer electronics, they enable displays and sensors; in photonics, they route light within chips.

Advantages include low loss over long distances, high bandwidth, and flexibility; limitations include attenuation, dispersion, bending losses, and sensitivity to environmental factors. The concept emerged in the 20th century, with significant progress during the 1950s–1980s, culminating in modern optical communications.