Theory analysis of the optical mode localized sensing based on coupled ring resonators

Area of Science:

• Photonics and Optical Engineering
• Nanotechnology
• Sensor Technology

Background:

• Optical mode localization in coupled resonators is a promising area for advanced sensing.
• Existing micro-mechanical sensors face limitations in sensitivity and accuracy.

Purpose of the Study:

• To develop an analytical model for optical mode localization in coupled ring resonators.
• To demonstrate high sensitivity and common-mode rejection for sensor applications.
• To explore the feasibility of practical sensor construction with inherent robustness to fabrication imperfections.

Main Methods:

• Utilized Mason's signal flow graph analysis to establish a theoretical model.
• Validated the model through simulation and Monte Carlo analysis.
• Investigated a four-port resonator structure enabling asymmetric and symmetric mode splitting.

Main Results:

• The analytical model accurately predicts optical mode localization.
• High sensitivity and common-mode rejection were achieved by analyzing the modal power ratio.
• Dual-channel calibration and high-sensitivity sensing were demonstrated simultaneously.
• Fabrication imperfections showed minimal impact (<6% in 90% of cases) on sensor performance.

Conclusions:

• The developed optical mode localized sensing offers superior sensitivity, accuracy, and anti-aliasing compared to micro-mechanical sensors.
• Practical, high-performance sensors are achievable with this approach.
• The platform allows for the construction of various sensors by coupling parametric perturbations with different physical measurands.