Design and optimization of liquid core optical ring resonator for refractive index sensing

Area of Science:

• Photonics and Optical Sensing
• Materials Science

Background:

• Whispering gallery modes (WGMs) are sensitive to changes in their surrounding environment.
• Liquid core optical ring resonators (LCORRs) offer potential for high-performance sensing applications.
• Thermal drift can significantly impact the accuracy of optical sensors.

Purpose of the Study:

• To theoretically analyze refractive index (RI) sensors based on WGMs in LCORRs.
• To investigate the influence of WGM order and resonator wall thickness on thermal stability and RI sensing performance.
• To provide guidance for developing thermostable LCORR-based RI sensors.

Main Methods:

• Detailed theoretical analysis of TE- and TM-polarized WGMs of various orders.
• Simulation of LCORR performance considering different wall thicknesses.
• Evaluation of RI sensing performance and thermal drift characteristics.

Main Results:

• Higher order WGMs necessitate thicker resonator walls for near-zero thermal drift.
• At thermostable wall thicknesses, WGMs of different orders exhibit comparable RI sensing performance.
• A very low RI detection limit is achieved at the optimal thermostable thickness.

Conclusions:

• The study provides theoretical insights into optimizing LCORR-based RI sensors for thermal stability.
• The findings guide the design of LCORRs with enhanced performance and reduced thermal sensitivity.
• LCORR technology shows promise for developing highly sensitive and stable RI sensors.