Fabrication, Characterization, and Sensor Applications of Polymer-Based Whispering Gallery Mode Microresonators

Area of Science:

• Optical Physics
• Materials Science
• Nanotechnology

Background:

• Whispering gallery mode resonators (WGMRs) use internal light reflections for sharp resonance peaks, enabling high-sensitivity optical sensing.
• Polymer characteristics significantly influence WGMR performance parameters like quality factor (QF) and sensitivity.

Purpose of the Study:

• To critically review the fabrication, characterization, and sensor applications of polymer-based WGMRs.
• To highlight the advantages of all-polymer, polymer-coated, and composite-functionalized WGMRs for enhanced sensing capabilities.

Main Methods:

• Review of fabrication techniques for polymer-based WGMRs.
• Analysis of characterization methods for WGMR performance metrics (QF, FSR, RI sensitivity).
• Evaluation of diverse polymer WGMR configurations (all-polymer, fiber-coated, composite-functionalized).

Main Results:

• Polymer-based WGMRs demonstrate design flexibility, biocompatibility, and tunable optical properties.
• All-polymer WGMRs offer integration capabilities, while polymer-coated fiber WGMRs enhance light-material interaction.
• (Polymer shell)-(inorganic core) composites synergize inorganic material QFs with polymer flexibility for superior optical properties.

Conclusions:

• Polymer-based WGMR sensors are highly promising for biomedical diagnostics, environmental monitoring, and industrial process control.
• Future research should focus on optimizing fabrication, exploring novel polymers, and integrating advanced signal processing for real-time, IoT-connected sensing platforms.