Quantitative coupled-mode model for a metal-dielectric-metal waveguide with a side-coupled cavity

Area of Science:

• Optoelectronics
• Nanophotonics
• Waveguide Optics

Background:

• Metal-dielectric-metal (MDM) waveguides offer unique optical properties.
• Fabry-Perot resonators are crucial for wavelength-selective devices.
• Accurate modeling is essential for designing advanced photonic devices.

Purpose of the Study:

• To propose and validate a Fabry-Perot model for analyzing MDM waveguides with side-coupled cavities.
• To investigate the wavelength-selective transmission behaviors of these structures.
• To explore potential applications in filters and sensors.

Main Methods:

• Utilizing the aperiodic Fourier modal method (a-FMM) to extract guided modes.
• Calculating scattering coefficients using a-FMM and normal-mode theory.
• Developing a comprehensive Fabry-Perot model for device analysis.

Main Results:

• The proposed Fabry-Perot model accurately predicts the fully vectorial behavior of the MDM waveguide system.
• Scattering coefficients were successfully computed, enabling detailed analysis.
• The model demonstrates reliability for quantitative analysis of optical devices.

Conclusions:

• The Fabry-Perot model provides a robust framework for understanding wavelength-selective transmission in MDM waveguides.
• This approach enables accurate design and optimization of photonic devices.
• The model's predictive power supports applications in wavelength-selective filters and refractive index sensors.