An Ultra-Fast Reconfigurable Higher-Order Topological Insulator

Topological photonics provides a new way to design and implement electromagnetic devices with unprecedented functions. According to reports, some low-order tunable topological devices have been developed, but the control of energy of those remains at the one-dimensional level. Here, we propose a printed-circuit board (PCB) based solution for building reconfigurable higher-order topological insulator (RHOTI) using PIN diodes, which enables fast fabrication and autonomous switching of topological functions, and enables higher dimensional regulation of energy. The designed RHOTI can quickly switch between low-order low-loss waveguides at 10.24GHz and higher-order corner states at 9.75GHz. This concept is also instructive for the design of reconfigurable metamaterials and photonic crystals.