Strong Resonance Effect in a Lossy Medium-Based Optical Cavity for Angle Robust Spectrum Filters

Spectrum filters with a wide viewing angleexploiting strong resonance effects in lossy media are demonstrated. The designed filters show significantly improved color purity and the angle-robust characteristic can be preserved up to +/- 65 degrees due to an interesting phase-cancellation effect. This strategy could provide new routes for numerous applications, such as image sensors and displays.