Ultrahigh efficiency and ultralow threshold energy all-optical switch based on state transition of defective waveguide networks

A novel design of ultrahigh efficiency and ultralow threshold energy all-optical switches based on local state transition of complete-connected optical waveguide networks (CCOWNs) is proposed. The generation of the ultra-narrow transmission peak and the ultra-strong photonic localization in network is attributed to the mutation of states, which are significant improvements in the performance of all-optical switch. First, the ultra-strong photonic localization induces the Kerr effect in nonlinear material, which transforms the transmission peaks into a transmission valley and results in the super-high efficiency. The efficiency of switch based on CCOWN with 11 unit cell (UC) and each UC possessing 7 nodes was calculated and found to be approximately 1.38x1039\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1.38 \times 10<^>{39}$$\end{document}, which is 13 orders of magnitude better than previously reported. Furthermore, the ultra-strong photonic localization also leads to the ultralow threshold energy. Calculations reveal that the threshold control energy of all-optical switch based on CCOWN only with 7 UC and each UC possessing 5 nodes is about 5.78x10-30\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$5.78 \times 10<^>{-30}$$\end{document} J, which is 5 orders of magnitude smaller than the best reported results. In addition, fitting formulas for the transmission and switching efficiency with UC number have been derived, and the results show that the switching efficiency increased exponentially with the UC number and nodes. This study not only presents a new model for designing all-optical switch with outstanding performance, but also provides the possibility for further practical use of all-optical switch, while deepening our insight into optical waveguide networks.