2018/08/27 by Xingping Zhou, Samit Kumar Gupta, Zhong Huang +5 · 1 citation
Physics and Astronomy · #physics.optics
paper · pdf · doi:10.1063/1.5043279
published as Applied Physics Letters 113, 101108 (2018) · To appear: Appl. Phys. Lett
arxiv created 2018/08/27 · arxiv updated 2018/09/11
Exceptional points (EPs) are degeneracies in open wave systems with coalescence of at least two energy levels and their corresponding eigenstates. In higher dimensions, more complex EP physics not found in two-state systems is observed. We consider the emergence and interaction of multiple EPs in a four coupled optical waveguides system by non-Hermitian coupling showing a unique EP formation pattern in a phase diagram. In addition, absolute phase rigidities are computed to show the mixing of the different states in definite parameter regimes. Our results could be potentially important for developing further understanding of EP physics in higher dimensions via generalized paradigm of nonHermitian coupling for a new generation of parity-time (PT) devices.