Hermetic sealing provides sunlight stable high refractive index waveguides for AR/VR/MR devices

High refractive index (RI) waveguides are essential components of miniaturized optical systems for AR/VR/MR devices. These waveguides can be comprised of high RI glass with nano-features imprinted on high RI resin coatings that provide surface relief gratings. A limitation is that high RI resins that contain titania nanoparticles are inherently unstable in sunlight. We describe a method for quantifying sunlight degradation of high RI titania-containing resins and demonstrate that hermetic sealing can suppress this degradation. We evaluate designs and materials for hermetically sealed high RI waveguides and show that their lifetimes can be extended from days to months or years of direct sunlight exposure.