S4 point-group terahertz metasurface realizes robust quasi-bound states in the continuum

https://www.eurekalert.org/news-releases/1148970

Summary: Designing sub-wavelength terahertz metasurfaces with S4 point-group symmetry traps electromagnetic radiation inside robust quasi-bound states in the continuum. The high structural symmetry suppresses radiative energy leakage, generating ultra-high Quality-factor resonance spikes that remain stable against structural fabrication imperfections. These resilient terahertz metasurfaces provide sensitive platforms for label-free chemical sensing and narrow-band filtering.