Unidirectional Transmission Waveguide with Polarization Locking Based on Metasurface

When the polarization state of a system is linearly locked to momentum and its scatterers do not induce spin flips, the resulting edge state with polarization locking can demonstrate unidirectional reflectionless transmission. In classical systems, the creation of polarization-locked edge states relies on two key symmetry transformations: electromagnetic duality (EM-duality) symmetry and parity time-reversal duality (PT-duality) symmetry. While EM-duality supports infinitesimal line-surface wave modes, PT-duality facilitates line-guided wave modes. However, the transmission power capacity of these modes is typically limited by the size of the model. To overcome this limitation, our work integrates both transformation physics mechanisms to develop a chiral waveguide with miniaturization, high power, and increased capacity through the design of a tailored metasurface structure. This innovative design approach opens up new avenues in the realms of photonics and electronics, particularly in the domains of information transmission and processing.