3D nanopatterning of volumetric lenses, waveguides, and metamaterials enabling ultra-dense, on-chip 3D optics

Here, we present Subsurface Controllable Refractive Index via Beam Exposure (SCRIBE), a direct-write lithographic approach that enables the fabrication of volumetric microscale gradient refractive index lenses, waveguides, and metamaterials. The basis of SCRIBE is multiphoton polymerization inside monomer-filled nanoporous silicon and silica scaffolds. Adjusting the laser exposure during printing enables 3D submicron control of the polymer infilling and thus the refractive index over a range of greater than 0.3 and chromatic dispersion tuning. A Luneburg lens operating at visible wavelengths, achromatic doublets, multicomponent optics, photonic nanojets and subsurface 3D waveguides were all formed.