IDEA #0OK4E4 Multi-Frequency Narrowband Gratings for RGB Reflection at Oblique Incidence

The use of resonant waveguide gratings (RWG) embedded in a glass-like matrix as angularly tolerant RGB reflection filters under oblique excitation. An inverse-design-based optimization method shows consistent convergence to a 1D grating structure, suggesting that RWG’s may represent a local optimal solution to obtain multi-frequency narrowband responses. TM and TE operation of these optimal gratings are separately considered and both single and multi-layer devices are presented. Such devices show potential to be used as transparent heads-up displays