Subwavelength Grating Double Slot Waveguide Racetrack Ring Resonator for Refractive Index Sensing Application

Area of Science:

• Photonics and Nanophotonics
• Optical Sensing
• Integrated Optics

Background:

• Standard slot waveguide resonators have limitations in light-matter interaction, impacting sensor sensitivity.
• Subwavelength gratings offer potential for enhanced light confinement and interaction.
• Racetrack ring resonators are widely used in sensing due to their compact size and high Q-factor.

Purpose of the Study:

• To propose and analyze a novel racetrack ring resonator design.
• To enhance light-matter interaction for improved sensor sensitivity.
• To investigate the performance of a subwavelength grating double slot waveguide in a resonator.

Main Methods:

• Numerical simulations using 2D and 3D finite element methods (FEM).
• Design and analysis of a racetrack ring resonator incorporating a subwavelength grating double slot waveguide.
• Optimization of grating period for maximum sensitivity.

Main Results:

• The proposed subwavelength grating double slot waveguide confines the electric field effectively.
• Achieved a sensitivity enhancement of approximately 2.5 times compared to standard slot waveguide resonators.
• Optimal sensitivity of 1000 nm/RIU obtained with a grating period of 300 nm.

Conclusions:

• The subwavelength grating double slot waveguide racetrack ring resonator offers significantly higher sensitivity.
• This design is a promising platform for developing highly sensitive lab-on-chip sensors.
• Potential applications in various fields requiring precise biochemical detection.