Nanoscale design of the local density of optical states

TL;DR

This paper introduces a method to tailor the local density of optical states in dielectric nanostructures by controlling phase distributions, enabling significant enhancements or suppressions of light emission at the nanoscale.

Contribution

It presents a novel design approach for dielectric nanostructures that manipulate the LDOS through phase control, allowing for tailored light-matter interactions.

Findings

Dielectric nanostructures can be engineered to significantly enhance LDOS by removing destructive interference.

The method achieves up to three orders of magnitude increase in LDOS for dielectric Mie resonators.

Designs can be generalized to enhance radiated power for various dipole configurations.

Abstract

We propose a design concept for tailoring the local density of optical states (LDOS) in dielectric nanostructures, based on the phase distribution of the scattered optical fields induced by point-like emitters. First we demonstrate that the LDOS can be expressed in terms of a coherent summation of constructive and destructive contributions. By using an iterative approach, dielectric nanostructures can be designed to effectively remove the destructive terms. In this way dielectric Mie resonators, featuring low LDOS for electric dipoles, can be reshaped to enable enhancements of three orders of magnitude. To demonstrate the generality of the method, we also design nanocavities that enhance the radiated power of a circular dipole, a quadrupole and an arbitrary collection of coherent dipoles. Our concept provides a powerful tool for high-performance dielectric resonators, and affords fundamental insights into light-matter coupling at the nanoscale.