Guided mode resonance device for optical beam tapping and imaging without rainbows

Stanford researchers have developed an optical coating that steers infrared and visual light in different paths while suppressing the typical undesired rainbow effect. The coating – a nanopatterned dielectric waveguide coated with an absorbing layer - extracts light of select wavelengths, well-defined polarization state, and/or angle of incidence. The extracted light can be efficiently redirected, making a compact, transparent eye tracker compatible with head-mounted/heads-up displays. The coating is ideal for augmented and virtual reality systems, displays, goggles, imaging, and optical switching applications.

Stage of Research
Researchers demonstrated ultra-thin, rainbow-free, eye tracking, optical coating device based on guided mode resonance that exhibits near-unity transmission. The tested 200-nm-thick Si₃N₄ slab waveguide was sandwiched between a quartz substrate and a 100-nm-thick SiO₂ capping layer designed for high transmission (>90%) over the whole visible spectrum. Prototype glasses are under development.