Observation of optical tunneling inhibition by a parabolic potential in twisted photonic lattices

Quantum tunneling is considered the cornerstone of many physical processes. So far, its evolution over time, especially under an external field superimposed on the periodic potential field, has not been directly observed experimentally due to the harsh requirements and extremely short time scale. In this paper, we fabricate twisted photonic lattices consisting of three-dimensional waveguide arrays and experimentally illustrate the optical tunneling process under the parabolic potential field through the photonic route. Optical tunneling inhibition is observed experimentally, and the reduced time required to achieve the maximum transfer of waveguides indicates the inhibition can be modulated by the parabolic potential. This provides a reliable means for subsequent experimental study of quantum tunneling under complicated external potential field.