On-Chip Multimode WGM Microresonator with Cross-Correlation Algorithm for Enhanced Sensing

Area of Science:

• Photonics and Optical Sensing
• Integrated Photonics
• Nanoscale Metrology

Background:

• Optical whispering-gallery-mode (WGM) microresonators offer high sensitivity for precision measurements.
• Current methods analyzing single WGM resonances struggle with multiple targets or environmental fluctuations.
• Distinguishing local perturbations from global changes is crucial for accurate sensing.

Purpose of the Study:

• To develop a novel sensing algorithm for WGM microresonators.
• To overcome limitations of single-mode analysis in complex environments.
• To enable accurate detection of local perturbations amidst environmental variations.

Main Methods:

• Proposed a multimode-based cross-correlation algorithm.
• Integrated on-chip silicon microresonators and pulley bus waveguides for multimode excitation.
• Validated the method through a proof-of-concept experiment detecting nanoparticles.

Main Results:

• The multimode algorithm effectively distinguishes local perturbations from global environmental fluctuations.
• Demonstrated successful nanoparticle detection in a temperature-varying environment.
• Validated the robustness and accuracy of the proposed sensing approach.

Conclusions:

• The multimode-based cross-correlation algorithm enhances WGM microresonator sensing capabilities.
• This approach offers a versatile solution for complex sensing scenarios, including molecule detection.
• Paves the way for high-sensitivity sensing using scalable integrated photonic platforms.