Transmittance and surface intensity in 3D composite plasmonic waveguides

Area of Science:

• Photonics and Nanotechnology
• Optical Engineering

Background:

• Composite plasmonic waveguides offer unique optical properties.
• Understanding modal behavior is crucial for device performance.

Purpose of the Study:

• To theoretically investigate composite plasmonic waveguide structures.
• To present expressions for modal expansion coefficients, optical transmittance, and surface intensity.
• To describe the behavior of dielectric channel waveguides with gold-coated sections.

Main Methods:

• Theoretical analysis of composite plasmonic waveguide structures.
• Derivation of expressions for modal expansion coefficients, optical transmittance, and surface intensity.
• Modeling the behavior of dielectric channel waveguides with gold-coated sections.

Main Results:

• Superstrate refractive index significantly controls modal beating and attenuation in gold-coated regions.
• Distinctive features in surface intensity and device transmittance are observed.
• The model accurately predicts device performance.

Conclusions:

• The presented model enables precise prediction of composite plasmonic waveguide performance.
• This research facilitates the design of highly sensitive miniature devices for evanescent refractometry and vibrational spectroscopy.
• The model can be extended for optimizing composite waveguides with nano-patterned overlayers.