Statistical measurements of quantum emitters coupled to Anderson-localized modes in disordered photonic-crystal waveguides

We present a statistical study of the Purcell enhancement of the light emission from quantum dots coupled to Anderson-localized cavities formed in disordered photonic-crystal waveguides. We measure the time-resolved light emission from both single quantum emitters coupled to Anderson-localized cavities and directly from the cavities that are fed by multiple quantum dots. Strongly inhibited and enhanced decay rates are observed relative to the rate of spontaneous emission in a homogeneous medium. From a statistical analysis, we report an average Purcell factor of 4.5±0.4 without applying any spectral tuning. By spectrally tuning individual quantum dots into resonance with Anderson-localized modes, a maximum Purcell factor of 23.8±1.5 is recorded, which is at the onset of the strong-coupling regime. Our data quantify the potential of Anderson-localized cavities for controlling and enhancing the light-matter interaction strength in a photonic-crystal waveguide, which is of relevance for cavity quantum-electrodynamics experiments, efficient energy harvesting and random lasing. © 2014 Optical Society of Americ

A nanophotonic probe for quantum electrodynamics in random cavities

Disorder in photonic-crystal slab waveguides can cause localization of light. Sapienza et al. observed that the interaction of localized light with embedded quantum dots is so strong that it yields a considerable Purcell enhancement of the emission rate. This coupling between emitters and these "random cavities" warrants a more detailed investigation