Numerical Analysis of Photon Absorption of Gate-defined Quantum Dots Embedded in Asymmetric Bull's-eye Optical Cavities
The study numerically investigated how a semiconductor substrate affects photon absorption efficiency in an asymmetric bull's-eye cavity containing a quantum dot. By adjusting the substrate distance, they found a further 1.6 times improvement in efficiency. This enhancement is driven by the substrate creating upward-preferred coupling and narrowing the far-field emission pattern, which are key to polarization-independent performance.