Xiao He, Dong-Lin Liu, Zhi-Bo Dang, Yi-jing Huang, Zhi-xin Liu, Li-heng Zheng, Zheng-chang Liu, Yu-chen Dai, and Zhe-yu Fang*
Abstract: Progress in photonic crystals (PhCs) enables the advanced manipulation of light propagation, leading to strong light–matter interactions and unconventional applications. To explore the physical nature and realize the precise and efficient control ofposition-dependent light–matter interactions, the direct deep-subwavelength characterization ofPhC states is pivotal. Here, the super-resolved visualization ofbulk states in the z-direction asymmetric dielectric PhC is realized by characterizing the radiative local density ofoptical states, including the etched hole area. An accelerating voltage scanning approach is proposed to selectively probe bulk states and substrates, elucidating the electron–matter interactions affected by the electron-beam energy. The bulk state energy is demonstrated to be confined inside structure holes as shown by the cathodoluminescence intensity mappings ofPhCs with different geometrical parameters, enabling the design ofa silicon-based high-quality cavity in the visible range. This work provides a deep investigation ofthe depth-dependent interaction between the electron beam and dielectric PhCs, promoting the characterization ofPhC delocalized modes. The deep-subwavelength detail ofbulk state benefits the future nanoscale manipulation oflight–matter interactions and the optimization of quantum emission devices.
Laser Photonics Reviews 03 July 2023 
Laser Photonics Reviews - 2023 - He.pdf
