# Three-dimensional nanophotonics with spatially modulated optical properties

## TL;DR

This paper introduces a new fabrication method called Implosion Fabrication that creates 3D nanostructures with precise control over optical properties for advanced photonic applications.

## Contribution

The novel contribution is the development of Implosion Fabrication, which combines lithography and nanoparticle assembly to achieve high-resolution 3D nanophotonics.

## Key findings

- Implosion Fabrication enables fabrication of 3D photonic crystals and quasicrystals with spatially modulated optical properties.
- The method allows for isotropic shrinking of hydrogel scaffolds with silver-enhanced features to create nanoscale structures.
- The technique opens new possibilities for non-Hermitian photonic systems with controlled gain and loss.

## Abstract

Nanophotonics has revolutionized the control of light-matter interactions in various fields of fundamental science and technology. In this work, we propose Implosion Fabrication (ImpFab) as a versatile nanophotonics fabrication platform providing the highest spatial resolution, material versatility, and full volumetric control. ImpFab uniquely combines top-down lithography with bottom-up nanoparticle assembly within a hydrogel scaffold, enabling precise control over optical material properties, such as refractive index, by adjusting printing parameters. We showcase the potential of ImpFab by fabricating three-dimensional photonic crystals and quasicrystals, as well as demonstrating optical structures with spatially modulated unit cell material properties. Our results highlight the potential of ImpFab in producing nanostructures with tailored optical functionalities, which are crucial for applications in sensing, imaging, and information processing, and opening new avenues in developing non-Hermitian photonic systems with spatially controlled gain and loss.

We combine hydrogel photopatterning with nanoparticle growth to form silver-enhanced features that isotropically shrink 1000 × in volume to realize nanoscale 3D structures with tunable optical properties.