We establish the angle-resolved thermal emission spectroscopy (ARTES) as a new platform to characterize the intrinsic eigenmode properties of non-Hermitian systems. This method can directly map the dispersion of meta-crystals within the light cone with a high angular resolution. To illustrate its usefulness, we demonstrate the existence of bound states in the continuum (BICs) and non-Hermitian Fermi arcs in a planar corrugated meta-crystal by measuring its angle-resolved thermal emission spectra. We show that change in the thickness of the meta-crystal can induce a band inversion between a BIC and a radiative state, and a pair of exceptional points emerge when the band inversion occurs. With this approach, the band mapping of non-Hermitian photonic systems can become a relatively straightforward task.
@article{arxiv.1911.06071,
title = {Angle-Resolved Thermal Emission Spectroscopy Characterization of Non-Hermitian Meta-Crystals},
author = {Fan Zhong and Kun Ding and Ye Zhang and Shining Zhu and C. T. Chan and Hui Liu},
journal= {arXiv preprint arXiv:1911.06071},
year = {2020}
}