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

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

Exploiting long-range disorder in slow-light photonic crystal waveguides

The interplay between order and disorder in photonic lattices opens up a wide range of novel optical scattering mechanisms, resonances, and applications that can be obscured by typical ordered design approaches to photonics. Striking examples include Anderson localization, random lasers, and visible light scattering in biophotonic structures such as butterfly wings. In this work, we present a profound example of light localization in photonic crystal waveguides by introducing long-range correlated disorder. Using a rigorous three-dimensional Bloch mode expansion technique, we demonstrate how inter-hole correlations have a negative contribution to the total out-of-plane radiative losses, leading to a pronounced enhancement of the quality factor, $Q$, and $Q/V$ cavity figures of merit in the long-range correlation regime. Subsequently, the intensity fluctuations of the system are shown to globally increase with the correlation length, highlighting the non-trivial role of long-range disorder on the underlying scattering mechanisms. We also explore the possibility of creating ultra-high quality cavity modes via inter-hole correlations, which have various functionalities in chip-based nonlinear optics and waveguide cavity-quantum electrodynamics.Comment: Updated version with DO