Observation of enhanced non-Hermitian sensing via transient reflectionless phenomena

Traditional resonant sensors are often constrained by low quality- ( Q-) factors and impedance mismatches, which severely limit their precision and sensitivity. In this study, we introduce an approach that leverages transient reflectionless phenomena within a simple open single-resonator system. Unlike conventional steady-state responses, which typically exhibit a single reflection peak, our method exploits transient responses to generate multiple reflection extrema, significantly enhancing the reflection contrast. Experimental and theoretical results demonstrate that this approach increases the reflection contrast by 67% in systems with a Q-factor of approximately 5. By enabling multiple high-contrast reflection extrema without the need for additional control mechanisms, our method overcomes the limitations imposed by low Q-factors and impedance mismatches. This breakthrough not only improves measurement precision and robustness but also paves the way for high-precision non-Hermitian sensing in applications such as information processing, environmental monitoring, and precision measurement.