Heungjoon Kim

Abstract Non-Hermitian photonic systems are known to exhibit unique phenomena, where non-Hermiticity is typically introduced by material loss or gain. Here, we propose and experimentally demonstrate unidirectional phenomena solely based on radiation. Our design is based on a double-lattice photonic crystal that has a linear dispersion with a single exceptional point, where the magnitudes of Hermitian and non-Hermitian couplings are canceled out in one direction.

T. Asano and S. Noda, “Photonic crystal devices in silicon photonics,” Proc. IEEE 106, 2183–2195 (2018). [Crossref] B.-S. Song, S. Jeon, H. Kim, D. D. Kang, T. Asano, and S. Noda, “High-Q-factor nanobeam photonic crystal cavities in bulk silicon carbide,” Appl. Phys. Lett. 113, 026849 (2018). [Crossref] T. Fan, H. Moradinejad, X. Wu, A. A. Eftekhar, and A. Adibi, “High-Q integrated photonic microresonators on 3C-SiC-on-insulator (SiCOI) platform,” Opt. Express 26, 25814–25826 (2018). [Crossref] X. Liu, A. W. Bruch, Z.

Abstract In order to enhance second-harmonic generation (SHG) efficiency in a waveguide-coupled photonic nanocavity, we introduce a reflector at the edge of the waveguide and investigate its influence on input power and SHG efficiency. SHG efficiency and critical input power of the reflective waveguide-coupled cavity are controlled by the reflection amplitude and phase delay of the reflector.