Virtually coupled resonators with modal dominance for improved sensitivity and bandwidth

Area of Science:

• Physics
• Engineering
• Sensor Technology

Background:

• Mode-localized sensors offer high sensitivity and common-mode noise rejection.
• Sensitivity stems from energy confinement in weakly coupled resonators, but confinement mechanisms are underexplored.

Purpose of the Study:

• To analyze energy confinement mechanisms in weakly coupled resonators.
• To propose and validate a novel concept of virtually coupled resonators for improved sensor performance.

Main Methods:

• Qualitative and quantitative analysis of energy confinement, introducing the concept of modal dominance.
• Development of virtually coupled resonators using frequency offset instead of physical coupling.
• Implementation of a double-closed-loop control scheme for enhanced bandwidth.

Main Results:

• Modal dominance explains energy confinement by internal resonator frequencies.
• Virtually coupled resonators achieve comparable amplitude ratio output to weakly coupled ones.
• Experimental validation shows a 2.7-fold increase in amplitude ratio sensitivity and a 4-fold bandwidth enhancement.

Conclusions:

• Modal dominance is key to spatial energy confinement in resonators.
• Virtually coupled resonators offer a novel, effective approach to sensor design.
• The proposed control scheme significantly boosts sensitivity and bandwidth, outperforming traditional methods.