Remote Dual-Cavity Enhanced Second Harmonic Generation in a Hybrid Plasmonic Waveguide

Area of Science:

• Nanophotonics
• Plasmonics
• Nonlinear Optics

Background:

• Efficient on-chip second harmonic generation (SHG) is crucial for advanced optical sensing and quantum photonic devices.
• Existing methods often face limitations in achieving high conversion efficiencies for integrated photonic platforms.

Purpose of the Study:

• To develop a novel scheme for significantly enhanced SHG in a hybrid plasmonic system.
• To explore the potential of dual cavity resonance for boosting nonlinear optical processes on-chip.

Main Methods:

• Fabrication of a hybrid waveguide system using a Cadmium Selenide (CdSe) nanobelt on a Gold (Au) film.
• Implementation of a remotely excited dual cavity resonance scheme involving horizontal and vertical Fabry-Pérot (FP) cavities.
• Utilizing interference of counter-propagating plasmonic modes excited by surface plasmons.

Main Results:

• Achieved a two orders of magnitude enhancement in SHG conversion efficiency, reaching 3.5 × 10^-4 W^-1.
• Demonstrated superior SHG emission originating from the synergistic effect of hybrid plasmon modes and FP cavity modes.
• Verified the effectiveness of remote excitation of surface plasmons for efficient SHG.

Conclusions:

• The developed dual cavity resonance scheme offers a powerful approach for enhancing on-chip SHG.
• This hybrid plasmonic device design opens new avenues for multifunctional nonlinear nanophotonic applications.
• The findings provide valuable insights for the development of next-generation integrated photonic devices.