An on-chip spectrometer: Chirped 3D photonic crystals have been created using colloidal particle diffusion in a photocurable medium. The variations in the lattice constant created a color gradient that spanned the entire visible range. By combining the functionality of chirped photonic crystals with a complementary metal-oxide-semiconductor sensor array, a miniaturized spectrometer system is developed (see picture).
- colloidal crystals
- photonic crystals