Conjugated topological cavity-states in one-dimensional photonic systems and bio-sensing applications.

Traditional photonic systems are endowed with brand new properties owing to the addition of topological physics with light. A conjugated topological cavity-states (CTCS) in one-dimensional photonic systems is presented, which has not only robust light transport but also ultra-high performances, such as high quality factor (high-Q) and perfect transmission. This extraordinary CTCS can address the bottleneck of typical topological photonic systems, which can only achieve robust light transport without maintaining high performance. Furthermore, the CTCS is especially suitable for bio-photonic sensing with high resolution requirements. An ultra-sensitivity of 2000 nm/RIU and a high-Q of 109 for detecting the concentration of SARS-CoV-2 S-glycoprotein solution are obtained. Notably, the CTCS not only opens new possibilities for advanced photonics but also paves the way for high performance in topological photonic devices.