Compact and high-resolution plasmonic wavelength demultiplexers based on Fano interference

Area of Science:

• Photonics and Plasmonics
• Optical Engineering
• Nanotechnology

Background:

• Fabry-Perot (FP) resonators are key components in optical devices.
• Achieving high resolution in wavelength demultiplexers is crucial for optical communication systems.
• Metal-insulator-metal waveguides offer unique plasmonic properties.

Purpose of the Study:

• To numerically demonstrate a compact plasmonic wavelength demultiplexer with high resolution.
• To investigate the role of coupled FP resonators in enhancing demultiplexing performance.
• To analyze the formation of Fano-line shapes and their impact on spectral resolution.

Main Methods:

• Numerical simulation of coupled Fabry-Perot resonators in metal-insulator-metal waveguides.
• Analysis of transmission spectra to identify Fano-line shapes.
• Characterization of resonator bandwidth and interference effects.

Main Results:

• A compact plasmonic wavelength demultiplexer with high resolution was successfully demonstrated.
• Emergence of narrowband right-angle resonators with narrower bandwidths than isolated FP resonators.
• Interference between narrowband and broadband resonators created sharp, asymmetric Fano-line shapes.
• Significantly improved wavelength demultiplexing resolution compared to isolated FP resonators.

Conclusions:

• The proposed coupled FP resonator design enables a highly efficient plasmonic wavelength demultiplexer.
• Fano-line resonances are effectively utilized to achieve superior wavelength resolution.
• This approach offers a promising pathway for developing advanced optical signal processing components.