Racetrack Ring Resonator-Based on Hybrid Plasmonic Waveguide for Refractive Index Sensing

Area of Science:

• Photonics and Plasmonics
• Nanotechnology
• Sensing Technologies

Background:

• Refractive index sensors are crucial for various applications, including environmental monitoring and medical diagnostics.
• Hybrid plasmonic waveguides (HPWGs) offer unique light-matter interaction properties for enhanced sensing.
• Racetrack ring resonators (RTRRs) are widely used in photonic sensing due to their compact size and high Q-factor.

Purpose of the Study:

• To numerically analyze a hybrid plasmonic waveguide-based racetrack ring resonator (HPWG-RTRR) for refractive index sensing.
• To investigate the impact of integrating a subwavelength grating (SWG) structure on sensor sensitivity.
• To optimize the HPWG-RTRR-SWG structure for enhanced sensing performance.

Main Methods:

• Comprehensive numerical analysis of the HPWG-RTRR structure.
• Integration of a subwavelength grating (SWG) into the racetrack configuration.
• Systematic variation of the SWG segment length to study its effect on sensitivity.

Main Results:

• The optimized HPWG-RTRR achieved a sensitivity of 275.7 nm/RIU.
• Integration of the SWG structure further enhanced light-matter interaction and device sensitivity.
• Sensitivity increased from 377.1 nm/RIU to 477.7 nm/RIU with SWG segment length increasing from 5 µm to 10 µm.

Conclusions:

• Hybrid plasmonic waveguides combined with subwavelength gratings show immense potential for highly sensitive photonic sensors.
• The length of the SWG segment is a critical parameter for maximizing sensor sensitivity.
• This study paves the way for developing next-generation, high-performance sensing devices.