Applications of Isosceles Triangular Coupling Structure in Optical Switching and Sensing

Area of Science:

• Photonics and Optical Engineering
• Materials Science
• Integrated Optics

Background:

• Waveguide-based devices have fixed optical properties post-fabrication, limiting dynamic control and practical applications.
• Existing integrated photonic devices lack tunability, hindering advanced functionalities.
• The need for reconfigurable optical components drives research into novel structures.

Purpose of the Study:

• To propose and investigate a novel isosceles triangular-coupling structure for tunable optical devices.
• To demonstrate the potential of this structure for optical switching using liquid crystals.
• To explore its application in high-sensitivity biochemical sensing, specifically for glucose detection.

Main Methods:

• Numerical and theoretical research using the finite difference time domain (FDTD) method.
• Verification of simulation results using coupled mode theory (CMT).
• Integration of liquid crystal (LC) materials to enable voltage-tunable refractive index.

Main Results:

• The proposed isosceles triangular-coupling structure exhibits a transmission spectrum with four distinct peaks due to side and angular modes.
• The structure's optical properties can be dynamically tuned by altering the applied voltage to the liquid crystal.
• Achieved high sensitivity for glucose detection (0.283 nm·L/g), surpassing existing literature values.

Conclusions:

• The proposed isosceles triangular-coupling structure offers a pathway to dynamically controlled optical devices.
• Its integration with liquid crystals enables effective optical switching.
• The structure shows significant promise for high-performance biochemical sensing applications.