Sensitivity enhancement in optical micro-tube resonator sensors via mode coupling

TL;DR

This paper proposes a liquid-filled silica micro-tube sensor with mode coupling to significantly enhance biochemical sensing sensitivity, achieving up to 1100nm/RIU through optimized coupling.

Contribution

It introduces a novel mode coupling strategy in micro-tube sensors that substantially increases sensitivity for biochemical detection.

Findings

Refractive index sensitivity increased to 967nm/RIU

Further optimization raised sensitivity to 1100nm/RIU

Design of robust, thick-walled micro-tube sensors achieved

Abstract

A liquid filled, low refractive index material inner-coated silica micro-tube has been proposed and studied as a coupled micro-resonator sensor to greatly enhance biochemical sensor sensitivity. Its unique coupling phenomenon has been analyzed and utilized to boost the refractive index sensitivity of the device to 967nm/RIU. Through optimization of the coupling strength between the two microresonators, further improvement in refractive index sensitivity up to 1100nm/RIU has been achieved. This mode coupling strategy allows us to design robust, thick-walled micro-tube sensors with ultra-high sensitivity which is useful in practical biochemical sensing applications.