Second harmonic generation from metallo-dielectric multilayered structures in the plasmonic regime

Area of Science:

• Materials Science
• Optics
• Nanotechnology

Background:

• Metallo-dielectric multilayered structures offer unique optical properties.
• Plasmonic effects can enhance nonlinear optical phenomena.
• Silver (Ag) and magnesium-fluoride (MgF2) are suitable materials for fabrication.

Purpose of the Study:

• To theoretically investigate second harmonic generation (SHG) in Ag/MgF2 multilayered structures.
• To analyze the influence of structural parameters on SHG efficiency in the plasmonic regime.
• To identify optimal geometries for enhanced SHG conversion.

Main Methods:

• Theoretical modeling of metallo-dielectric multilayered structures.
• Systematic analysis of four elementary cell configurations: (Ag/MgF2)N, (MgF2/Ag)N, (Ag/MgF2/Ag)N, and (MgF2/Ag/MgF2)N.
• Investigation of the role of layer thickness, number of periods, and output medium.

Main Results:

• Predicted SHG conversion efficiency up to three orders of magnitude higher than in the non-plasmonic regime.
• Identification of specific geometries yielding maximal conversion efficiencies.
• Demonstration of the robustness of SHG in the plasmonic regime against layer thickness variations.
• Potential for an almost five-orders-of-magnitude enhancement with optimal output medium selection.

Conclusions:

• Ag/MgF2 multilayered structures exhibit significant potential for efficient second harmonic generation.
• Plasmonic effects, including short-range/long-range plasmons and leaky waves, are crucial for enhanced SHG.
• The study provides guidelines for designing robust and highly efficient plasmonic nanostructures for nonlinear optics.