Suppression of backscattered diffraction from sub-wavelength 'moth-eye' arrays

Area of Science:

• Nanotechnology
• Biomimetics
• Optics

Background:

• Moth eyes and wings feature nanoscale structures that minimize light reflection.
• Artificial moth-eye surfaces are used in antireflection and antiglare technologies.
• Regular arrays can cause iridescence due to light diffraction at high incidence angles.

Purpose of the Study:

• To suppress iridescence in artificial moth-eye arrays at high angles of incidence.
• To develop a novel tiled domain design inspired by natural moth-eye structures.
• To improve antireflection and stealth properties of artificial surfaces.

Main Methods:

• Fabrication of artificial moth-eye surfaces using a tiled domain design.
• Incorporation of high optical rotational symmetry in the pillar architecture.
• Testing a silicon-based tiled design with 9 different orientations of hexagonal arrays.

Main Results:

• Achieved significant suppression of iridescence caused by light diffraction.
• Demonstrated high levels of diffraction order power reduction.
• A specific tiled design showed a ~96% reduction in the -1 diffraction order intensity.

Conclusions:

• Natural moth-eye structures likely evolved tiled domains for efficient antireflection and to avoid high-angle diffraction.
• The bio-mimetic tiled domain design offers improved antireflection and stealth properties.
• This design has potential for advanced antiglare and stealth applications.