Quasicrystal Photonic Metasurfaces for Radiation Controlling of Second Harmonic Generation

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Photonic metasurfaces are 2D structured media manipulating light at the subwavelength scale.
• While linear optical metasurfaces are well-studied, nonlinear optical regimes are emerging.
• The role of global symmetry in nonlinear metasurfaces remains underexplored compared to local symmetry.

Purpose of the Study:

• To investigate the influence of global symmetry in nonlinear metasurfaces.
• To design and fabricate nonlinear optical quasicrystal metasurfaces.
• To understand how tiling schemes and local meta-atom symmetry affect nonlinear optical phenomena.

Main Methods:

• Design and fabrication of nonlinear optical quasicrystal metasurfaces using geometric-phase-controlled plasmonic meta-atoms.
• Utilizing Penrose tiling and hexagonal quasicrystalline tiling schemes.
• Analysis of far-field radiation patterns of second harmonic generation (SHG) waves.

Main Results:

• Far-field radiation behavior of SHG waves is dependent on both quasicrystal tiling schemes and local meta-atom symmetry.
• Demonstrated control over nonlinear optical responses through global and local symmetries.
• Successful fabrication of designed quasicrystal metasurfaces.

Conclusions:

• Global symmetry is a critical factor in nonlinear optical metasurfaces, alongside local symmetry.
• The findings offer a new paradigm for designing advanced nonlinear optical sources.
• Metasurface crystals provide a versatile platform for tailored nonlinear optical functionalities.