Experimental Observation of Interorbital Coupling

Interorbital coupling refers to the possibility of exciting orbital states by otherwise orthogonal noninteracting modes, a forbidden process in photonic lattices due intrinsic propagation constant detuning. In this Letter, using femtosecond (fs) laser writing technique, we experimentally demonstrate that fundamental and excited can couple each other when located at different spatial positions. We perform full characterization an asymmetric double-well-like potential implement scan method effectively map dynamics along coordinate. Our observation also constitutes direct solution for mode converter device, which could be any position inside glass chip. By taking advantage phase structure higher-order modes effective negative generated, propose trimer configuration as beam splitter, great relevance multiplexing interference-based concatenated operations.Received 4 March 2021Accepted 15 July 2021DOI:https://doi.org/10.1103/PhysRevLett.127.066601© 2021 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasClassical transportElectronic structureElectronic atoms & moleculesLattice dynamicsLocalizationStructural propertiesTransport phenomenaCondensed Matter, Materials Applied Physics