Compact on-chip plasmonic light concentration based on a hybrid photonic-plasmonic structure

Area of Science:

• Photonics
• Plasmonics
• Nanotechnology

Background:

• Achieving tightly concentrated optical fields is crucial for various nanophotonic applications.
• Existing methods often face limitations in terms of device size and efficiency.

Purpose of the Study:

• To introduce a novel hybrid photonic-plasmonic device, the plasmomic light concentrator (PLC), for efficient light concentration.
• To numerically investigate the performance and underlying physical mechanisms of the PLC.

Main Methods:

• Design and numerical simulation of a triangle-shaped metal taper on a dielectric waveguide.
• Analysis of light coupling from the waveguide to the plasmonic region and focusing to the taper apex.
• Investigation of the interplay between mode beat, nanofocusing, and weak resonance effects.

Main Results:

• The PLC achieves vertical coupling and light focusing to nanoscale dimensions (~10nm).
• A field concentration factor (FCF) of ~13 was demonstrated with a device length < 1 μm and tip radius of 20 nm.
• High efficiency (FCF of 5-10) was maintained over a broad wavelength range (700-1,100 nm) with a reduced device length (~400 nm).

Conclusions:

• The PLC offers a super compact and highly efficient solution for optical field concentration.
• The device's performance is governed by the synergistic effects of mode beat, nanofocusing, and weak resonance.
• This technology holds promise for advanced nanophotonic applications requiring extreme light confinement.