Three-dimensional femtosecond laser nanolithography of crystals

Optical properties of materials are based on their chemistry and the inherent subwavelength architecture, although the latter remains to be characterized in depth. Photonic crystals and metamaterials have proven this by providing access through surface alterations to a new level of light manipulation beyond the known natural optical properties of materials. Yet, in the past three decades of research, technical methods have been unable to reliably nanostructure hard optical crystals beyond the material surface for in-depth optical characterization and related applications.