Hybrid plasmonic waveguide for low-loss lightwave guiding

Area of Science:

• Photonics and Plasmonics
• Materials Science
• Optical Engineering

Background:

• Plasmonic waveguides offer high light confinement but suffer from significant propagation loss.
• Existing dielectric waveguides have lower confinement and higher loss compared to plasmonic structures.

Purpose of the Study:

• To propose and fabricate a hybrid plasmonic waveguide structure for low-loss lightwave guiding.
• To reduce propagation loss by confining the guided mode in dielectric layers.
• To investigate the optical properties of the novel waveguide at a wavelength of 1.31 micrometers.

Main Methods:

• Embedding a thin gold (Au) stripe within dual slab waveguides featuring high refractive-index contrast.
• Fabrication of 5 nm-thick gold stripe optical waveguides.
• Measurement of optical properties, specifically propagation loss, at a 1.31 micrometer wavelength.

Main Results:

• The hybrid structure confines the guided mode effectively within the dielectric core layers.
• Achieved significantly reduced propagation loss, measuring less than 1.0 dB/cm.
• Demonstrated a guided mode combining characteristics of long-range surface plasmon polariton strip and dielectric slab modes.

Conclusions:

• The proposed hybrid plasmonic waveguide structure enables low-loss light guiding.
• This design offers a promising solution for enhancing the efficiency of optical devices.
• The waveguide's performance is attributed to the synergistic confinement of light in both plasmonic and dielectric components.