基于单个槽波导微环谐振器法诺共振的折射率传感

Refractive Index Sensing Based on the Fano Resonance of A Single Slot Waveguide Microring Resonator

摘要:

法诺线型的不对称和窄线宽特性有利于实现具有高传感灵敏度和低可探测极限的折射率传感。采用三维时域有限差分法,基于槽波导设计了微环谐振器和法布里-珀罗腔的耦合结构,实现了法诺线型谱线,并利用其提升折射率传感器的性能。不同于已报道的多微环级联等复杂结构,基于单个槽波导微环实现了法诺线型谱线,并在波长探测传感方案下得到传感灵敏度为500nm/RIU,可探测极限为4.00×10-5RIU；在强度探测传感方案下,传感灵敏度为7.24×10⁴dB/RIU,可探测极限为5.52×10-6RIU。

Abstract:

The asymmetry and narrow linewidth properties of the Fano line shape are conducive to the realization of refractive-index sensing with high sensitivity and low detection limit. In this study, the coupled structure of the microring resonator and the Fabry-Perot cavity was designed based on the slot waveguide, using the three-dimensional time-domain finite-difference method. The Fano line shape resonance was realized and utilized to improve the performance of refractive index sensors. In contrast to reported complex structures such as multiple micro-ring cascades, a sensitivity of 500nm/RIU and detection limit of 4.00×10-5RIU were achieved under the wavelength tracking scheme based on the Fano lineshape resonance of the single-slot waveguide microring resonator. The sensitivity was 7.24×10⁴dB/RIU for a detection limit of 5.52×10-6RIU under the intensity tracking scheme.