Abstract
Nonlinear phenomena are investigated in a topological photonic valley Hall insulator (VHI) using a Kagome system designed to have localized topological boundary state (TBS) at telecommunications wavelengths. Valley Hall topologically protected nonlinear phenomena are demonstrated. Similar transmission properties and parametric wavelength conversion of up to -12 dB are experimentally achieved using sub-milliwatt average powers in a zigzag interface without back-scattering, compared with a straight interface. Furthermore, a 7 dB slow light enhancement is observed in the conversion efficiency near the red edge in the transmission band of the boundary state, demonstrating how slow light-induced backscattering may be circumvented by leveraging the topologically protected boundary state. A Kerr-induced delocalization of the valley Hall topological state (VHTS) is further experimentally observed, which can be harnessed to control the properties of topological edge states.
Nonlinear phenomena are investigated in a topological photonic valley Hall insulator (VHI) using a Kagome system. Valley Hall topologically protected nonlinear parametric wavelength conversion of up to -12 dB conversion efficiency is experimentally demonstrated, including 7 dB slow light enhancement near the red edge in the transmission band of the boundary state. This work demonstrates how slow light-induced backscattering may be circumvented by leveraging the topologically protected boundary state. image