Spectral-splitter coatings in laser systems for the visible and infrared regions

Abstract

This paper describes examples of the synthesis and fabrication of optical coatings that operate in the mid-IR region and the visible region simultaneously. In particular, it tells how to separate the radiations of CO2 and He-Ne lasers by means of interference coatings that transmit (or reflect) the radiation of a CO2 laser and simultaneously reflect (or transmit) pilot radiation in the visible region, including the radiation of a He-Ne laser. Structures based on doped BaF2 films are considered that reflect the visible range and simultaneously operate as antireflection coatings in the IR region. The use of metal-dielectric coatings makes it possible to implement structures that reflect radiation in the IR region and simultaneously transmit radiation in the visible and near-IR regions of the spectrum. Examples are given of the synthesis and practical implementation of this type of coatings.