How Chiral Metasurfaces Are Transforming Data Encoding

What Is Chirality? Exploring the Science Behind Symmetry

In nature, symmetry is a fundamental feature of many things, including the components of DNA and light itself. It is possible that two molecules almost identical to each other differ not in their composition or shape, but in their orientation, a concept called “chirality”.

Chirality can be explained in its simplest form as the reason why our left hand differs from our right hand, despite both hands being identical in their shape, structure, and function.

Chirality plays a fundamental role in biology, with natural selection having selected exclusively “right-handed” DNA molecules, sugar, and amino acids (the base component of proteins).

The same type of phenomenon can be at play with light, which can be polarized toward the left or right, changing the direction of its electric field.

When exposing a chiral molecule to polarized light, the reaction differs depending on the direction of the light polarization.

This is a well-known phenomenon in physics, but until now it was too weak to be used in practical applications. This might have changed thanks to the work of researchers at the École Polytechnique Fédérale de Lausanne (EPFL – Switzerland), the Australian National University, and the University of South Australia.

They published their results in Nature Communications¹, under the title “Chirality encoding in resonant metasurfaces governed by lattice symmetries”.

How Meta-Atoms Enable Tunable Chiral Metasurfaces

Scientists have been developing new types of materials, called metamaterials, for a few decades. Metamaterials derive new properties not found in nature, not from their composition alone, but from how their internal structure is designed.

Meta-atoms are the blocks from which metamaterials are made.

The researchers have developed 2D lattices composed of tiny elements (the meta-atoms) that can easily tune their chiral properties.

Source: Nature

By varying the orientation of meta-atoms within a lattice, scientists can control the resulting metasurface’s interaction with polarized light.

Source: Nature

A Chiral Toolkit for Light-Based Data Encoding

Previous attempts to use chirality to control interaction with light had limited success. In large part, this was due to a too difficult approach, using very complex meta-atom geometries.

Instead, the Swiss and Australian researchers leveraged the interaction between the shape of the meta-atoms and the symmetry of the lattice. They used a metasurface made of germanium and calcium difluoride.

Source: Nature

As a result, they could produce a predictable chiral behavior, tunable by simple parameters, hence creating a universal toolkit for on-demand chiral design.

The inverted metasurface pattern was written using electron beam lithography.

Dual Data Transmission

As a proof-of-concept, the researchers created an image with 2 layers of data encoded by a metasurface, one with normal light and one with polarized light.

Source: Nature

The “transmission image” was encoded by the size of the meta atoms, and could be decoded using unpolarized light. The “chiral image” was encoded by the orientation of the meta atoms, revealed when exposed to circularly polarized light.

“This experiment showcased our technique’s ability to produce a dual layer ‘watermark’ invisible to the human eye, paving the way for advanced anticounterfeiting, camouflage and security applications,”

Ivan Sinev – Bionanophotonics Systems Lab researcher.

The light used was in the middle of the infrared range, making it relatively low-cost and easy to use.

Real-World Applications of Chiral Encoding Technology

The first field of application of this technology is for advanced encryption, tagging, and other anticounterfeiting measures.

Using this technique, a unique and secret level of encoding, only doable with this chiral toolkit on hand, could be used to certify the authenticity of bank notes, ID cards, payment systems, and other identification systems.

Another option could be to use this technique to create sensors sensitive to chiral structures. As most biological molecules are chiral, this could be used in distinguishing between left- and right-handed biomolecules.

Source: Nature

As the system can be tuned along a gradient, it could also allow for scalable sensing of chiral molecules.

“We can use chiral metastructures like ours to sense, for example, drug composition or purity from small-volume samples. It could make the difference between a medicine and a toxin,”

Felix Richter – Bionanophotonic Systems Lab researcher.

Polarized light is also very important in advanced computing systems emerging as a potential alternative to current silicon chips. This includes photonics and optical computing, as well as quantum computing and quantum photonics.

This sort of tunable chiral system could be used to make further progress in the control of polarized light, increasing the precision and reducing the cost of such tools for new types of advanced computing.

Top Publicly Traded Laser & Photonics Company

Coherent (II-VI Marlow): A Leader in Laser Innovation

As photonics and metamaterials become more important in many industries, the main tools for these techniques, lasers, are also seeing their market grow.

Coherent is a large industrial conglomerate with 26,000+ employees and a leader in laser technology. It resulted from the merger of advanced material II-VI Marlow with laser maker Coherent.

The company is an expert in advanced materials used in lasers, optics, and photonics, such as indium phosphide, epitaxial wafers, and gallium arsenide.

It grew largely thanks to multiple acquisitions over the last decade, from $600M in revenues in 2013 to $4.7B in 2024.

The company derives 29% of its revenues from lasers directly, with the rest linked to associated equipment like optical fiber and electronics. The instrumentation category mostly includes life sciences and medical applications.

Source: Coherent

The presence of the company in advanced materials like thermophotovoltaics (which we discussed in a previous article), silicon carbide, lasers, and electronics helps it benefit from structural trends like the growth of precision manufacturing, additive manufacturing (3D printing), electrification, and renewable energies.

The company has recently separated its silicon carbide business into a new entity, owned at 75% by Coherent, with the rest owned equally by its partners Mitsubishi Electric (bringing silicon carbide power IP) and Denso (bringing its activity as an automotive supplier on electrification and power semiconductors).

This is because silicon carbide is increasingly its own technology, separated from laser, mostly used in high-power applications like EVs, batteries, and renewable energy. (You can read more about silicon carbide in our dedicated investment report about this technology.)

Coherent’s lasers make it a leader in LIDAR and 3D-digital sensing, including for self-driving applications, biotech Next Generation Sequencing (NGS) Flow Cells, and lasers for semiconductor manufacturing. It expects its main markets to grow at 8-20%.

Source: Coherent

Other potential new applications of lasers, like direct energy weapons, photonic computing, nuclear fusion, and spacetech, could all equally help sustain the long-term growth of the company.

Overall, Coherent is as close as it can get to a “pure play” publicly traded laser company for investors interested in the sector, with strong vertical integration and 3,100+ patents protecting its innovations.

As photonics progresses, it will progressively increase the demand for ultra-fast, ultra-precise laser systems, as well as lasers used in optical telecommunications.

Latest Coherent (COHR) Stock News and Developments

Study Referenced

^{1. Sinev, I., Richter, F.U., Toftul, I. et al. Chirality encoding in resonant metasurfaces governed by lattice symmetries. Nature Communications 16, 6091 (2025). https://doi.org/10.1038/s41467-025-61221-2}