The research group of Prof. Sabat at RMC has recently published on the fabrication of large-scale hierarchical macroscopic Moiré (multi-period) gratings on azobenzene molecular glass thin films on a glass wafer. These novel structures were inspired by the surface features found on Peruvian lily flower petals. Optica (previously known as The Optical Society of America) recently featured these new surface structures on their Instagram feed. Further details are found at Applied Optics Vol. 61, Issue 18, pp. 5428-5434 (2022)
Pairwise images showing the similarity between the Peruvian lily flower petal structure and the Moiré diffraction grating structure.
Photonic quasicrystals with magnified inset showing the microscopic structure of the grating, as measured using an atomic force microscope (AFM).
Microscopic views - A series of three diffraction gratings with different symmetries, and their corresponding Fourier transforms.
These images are from the paper Large-area photonic crystals, quasicrystals, and Moiré quasicrystals fabricated on azobenzene molecular glass films by pyramidal interference lithography
(Optical Materials Express Vol. 12, No. 11 / 1 Nov 2022)
Moiré photonic crystals and quasicrystals. (a) Schematic of the formation of a Moiré pattern with 4-fold symmetry. (b - e) AFM images and corresponding simulations of gratings with 3-fold symmetry, 8-fold symmetry, and 12-fold symmetry.