PERSPECTIVES
Moiré photonic crystals
MOIRÉ PHOTONIC CRYSTALS: FROM FABRIC TO MAGIC
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Marion LAVIGNAC 1, Hai Son NGUYEN 2, Xavier LETARTRE 1, Ségolène CALLARD 1, Lydie FERRIER 1, *
1
École Centrale de Lyon, INSA Lyon, Université Claude Bernard Lyon 1, CPE Lyon, CNRS, INL, UMR5270 Ecully 69130, France
2
CNRS-International-NTU-Thales Research Alliance( CINTRA), IRL 3288, Singapore 637553 * lydie. ferrier @ insa-lyon. fr
Moiré patterns have recently become a very active field in nanophotonics. Those structures exhibit novel photonic properties unattainable with traditional photonic crystals. Especially, moiré magic configurations have been shown to allow intriguing slow light modes with zero group velocity. Starting from macroscopic moiré patterns in the everyday life, we will then shift to the subwavelength scale of moiré photonic crystals and detail some of their unusual properties.
https:// doi. org / 10.1051 / photon / 202613758
This is an Open Access article distributed under the terms of the Creative Commons Attribution License( https:// creativecommons. org / licenses / by / 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Have you ever noticed those weird wavy and flowing shapes magically appearing on your laptop screen when you try to take a picture of it with your smartphone? This is a moiré pattern. Originally, moiré [ mwaʁe ] was an adjective describing fabrics with wavy effects, obtained by strongly pressing the fabrics to flatten the fibres and modify light reflection. This technique was brought from Bagdad to England by the explorers from the 14th century, and reinvented during the 1740s by John Bagder who designed a machine named calender consisting of a heavy rectangular piece of rock used to press the fabrics. This invention gave the monopole of moiré fabrics in Europe to England. In 1753, the French government, worried by the French dependence on England’ s moiré fabrics, invited John Bagder to settle in France, in Lyon, and transmit his knowledge to French weavers. Later, the calender underwent many developments and improvements, and Lyon became the French capital of moiré fabrics.
Moiré fabrics are not the only support to host moiré patterns. Similar wavy or beating shapes can be seen in curtains, on a bridge with grid barriers, or even if you take a picture of your computer’ s screen with your smartphone( Figure 1). In each case, the effect results from the superposition of two frames or lattices: two fabrics’ lattices, two grid barriers, the computer’ s screen resolution and the picture resolution. Hence, moiré patterns extended to name every large-scale pattern formed by the superposition of two smaller-scale patterns.
Today, moiré patterns are wellknown in art and industry, sometimes desired and sometimes hated. Indeed, moiré effects can destroy the
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