Polarization multiplexing multichannel high-Q terahertz sensing system

Terahertz functional devices with high-Q factor play an important role in spectral sensing, security imaging, and wireless communication. The reported terahertz based on the electromagnetic induction transparency (EIT) effect cannot meet needs of practical applications due to low-Q factor. Therefore, increase Q-factor resonance, researchers introduced concept bound state continuum (BIC). In quasi-BIC state, metasurface can be excited by incident wave provide resonance a because condition that resonant BIC is orthogonal not satisfied. split ring resonator (SRR) one most representative artificial microstructures field, it shows great potential BIC. this paper, classical single-SRR array structure, we combine large small SRR change mode inner outer changing radius SRR. parameter-tuned verified continuous modulation parameters system could make pair states strongly coupled, coherent cancellation will cause linewidth disappear, thus forming Compared symmetry-protected BIC, dual-SRR designed paper has multiple accidental BICs realizes multichannel multiplexing X-polarization Y-polarization. It provides brilliant platform for high-sensitivity optical sensor array, low threshold laser efficient harmonic generation.