3-dB couplers,which are commonly used in photonic integrated circuits for on-chip information processing,precision measurement,and quantum computing,face challenges in achieving robust performance due to their limited...3-dB couplers,which are commonly used in photonic integrated circuits for on-chip information processing,precision measurement,and quantum computing,face challenges in achieving robust performance due to their limited 3-dB bandwidths and sensitivity to fabrication errors.To address this,we introduce topological physics to nanophotonics,developing a framework for topological 3-dB couplers.These couplers exhibit broad working wavelength range and robustness against fabrication dimensional errors.By leveraging valley-Hall topology and mirror symmetry,the photonic-crystal-slab couplers achieve ideal 3-dB splitting characterized by a wavelength-insensitive scattering matrix.Tolerance analysis confirms the superiority on broad bandwidth of 48 nm and robust splitting against dimensional errors of 20 nm.We further propose a topological interferometer for on-chip distance measurement,which also exhibits robustness against dimensional errors.This extension of topological principles to the fields of interferometers,may open up new possibilities for constructing robust wavelength division multiplexing,temperature-drift-insensitive sensing,and optical coherence tomography applications.展开更多
基金supported by National Key Research and Development Program of China(Grant No.2022YFA1404304)National Natural Science Foundation of China(Grant Nos.62035016,12274475,12074443,62105200)+1 种基金Guangdong Basic and Applied Basic Research Foundation(Grant Nos.2023B1515040023,2023B1515020072)Fundamental Research Funds for the Central Universities,Sun Yat-sen University(23lgbj021,23ptpy01)。
文摘3-dB couplers,which are commonly used in photonic integrated circuits for on-chip information processing,precision measurement,and quantum computing,face challenges in achieving robust performance due to their limited 3-dB bandwidths and sensitivity to fabrication errors.To address this,we introduce topological physics to nanophotonics,developing a framework for topological 3-dB couplers.These couplers exhibit broad working wavelength range and robustness against fabrication dimensional errors.By leveraging valley-Hall topology and mirror symmetry,the photonic-crystal-slab couplers achieve ideal 3-dB splitting characterized by a wavelength-insensitive scattering matrix.Tolerance analysis confirms the superiority on broad bandwidth of 48 nm and robust splitting against dimensional errors of 20 nm.We further propose a topological interferometer for on-chip distance measurement,which also exhibits robustness against dimensional errors.This extension of topological principles to the fields of interferometers,may open up new possibilities for constructing robust wavelength division multiplexing,temperature-drift-insensitive sensing,and optical coherence tomography applications.
