Controlled cavity-QED using a photonic crystal waveguide-cavity system

TL;DR

This paper presents a photonic crystal waveguide-cavity system that enables precise control of single photon cavity-QED processes, achieving high Purcell factors and efficient photon emission for integrated quantum photonics.

Contribution

The authors develop an analytical framework for controlling cavity-QED in photonic crystal waveguides, validated by numerical simulations, enabling advanced nano-engineering of quantum light-matter interactions.

Findings

Achieved Purcell factors >1000

On-chip single photon beta factors ~80%

Controlled weak and strong coupling regimes

Abstract

We introduce a photonic crystal waveguide-cavity system for controlling single photon cavity-QED processes. Exploiting Bloch mode analysis, and medium-dependent Green function techniques, we demonstrate that the propagation of single photons can be accurately described analytically, for integrated periodic waveguides with little more than four unit cells, including an output coupler. We verify our analytical approach by comparing to rigorous numerical calculations for a range of photonic crystal waveguide lengths. This allows one to nano-engineer various regimes of cavity-QED with unprecedented control. We demonstrate Purcell factors of greater than 1000 and on-chip single photon beta factors of about 80% efficiency. Both weak and strong coupling regimes are investigated, and the important role of waveguide length on the output emission spectra is shown, for vertically emitted emission and output waveguide emission.