Circularly polarized light is a specialized form of light whose electric field rotates as the wave travels. That rotation can be either left-handed or right-handed, and the distinction is useful because the two states can carry separate channels of information. Conventional technologies often require chiral molecules—molecules whose mirror images cannot be superimposed—to generate or manipulate this type of light. Creating such molecules, however, can involve complicated chemical synthesis, while mixtures of opposite-handed structures can cancel one another’s optical effects.

The KAIST team, led by Professor Dong Ki Yoon of the Department of Chemistry, developed a different strategy based on controlling molecular organization rather than molecular asymmetry. The researchers worked with achiral, rod-shaped liquid-crystal molecules that are individually symmetric. Under carefully controlled conditions, these molecules were confined within microscale spaces and encouraged to assemble into pinwheel-shaped structures. Although the molecules themselves had no inherent handedness, their collective arrangement could adopt either a clockwise or counterclockwise configuration.

The principle resembles the way a flat sheet of paper can be folded into pinwheels that turn in opposite directions. The paper remains the same, but the arrangement of its folds determines the final handedness. In a similar way, the liquid-crystal molecules used in the study were chemically unchanged, while the geometry of their assembly generated a chiral structure. This distinction is important because it separates the origin of the optical response from the chemical identity of the material itself.

The researchers first induced the molecules to self-assemble into microscopic pinwheels. A major challenge was preventing both handednesses from forming at the same time. If clockwise and counterclockwise structures appear in equal or nearly equal numbers, their optical responses can weaken or cancel, making it difficult to produce a strong, uniform signal across a large area. To solve this problem, the team introduced a chiral additive in a concentration of less than 1 percent of the total material. Rather than acting as the primary optical material, the additive served as a molecular guide that selected one pinwheel orientation.

This small amount of chiral material was sufficient to bias the self-assembly process and align the pinwheels with a common handedness. The result was a large-area array of microscale structures with a consistent orientation. The researchers then permanently transferred or replicated the arrangement onto polymer nanofibers, creating a stable chiral platform that could be used as a surface for other optical materials. This replication step is particularly significant because it suggests that the pinwheel architecture can be integrated into flexible or nanoscale devices rather than remaining limited to a temporary liquid-crystal state.

To test whether the structure could control light, the team coated the patterned platform with a conventional luminescent material. When excited, the luminescent coating emitted circularly polarized light. Crucially, the direction of that polarization was determined by the handedness of the underlying pinwheel array rather than by a change in the light-emitting substance. Reversing the orientation of the pinwheels switched the emitted light from one rotational direction to the other, demonstrating that the optical function originated from structural organization.

The finding illustrates a broader design principle in materials science: a material’s properties can emerge from how its building blocks are arranged, even when those building blocks lack the desired property individually. The same idea appears in photonic crystals, metamaterials, liquid-crystal devices, and biological structures, where nanoscale geometry can determine how light, sound, or electrons move. In this case, the pinwheel array creates a chiral optical environment that influences the interaction between the luminescent coating and the emitted electromagnetic field. The structure effectively transfers handedness to light without requiring a fully chiral emitter.

According to the researchers, the platform could help simplify the development of optical technologies that rely on polarization. Displays might use structurally controlled circularly polarized emission to improve light management and reduce optical losses. In augmented- and virtual-reality systems, chiral structures could be incorporated into lightweight polarization-control elements. Optical communication systems could potentially use left- and right-handed polarization states as distinct information channels, while security labels could exploit the ability of a patterned surface to produce a recognizable polarization signature. Polarization sensors may also benefit from materials whose response can be tuned through geometry rather than chemical redesign.

The study was led by first author Jeong Yeon Han, a Ph.D. candidate, in collaboration with scientists from Chungnam National University, Ajou University, Yonsei University, and Japan’s RIKEN. Han explained that conventional methods often produce left- and right-handed structures together, reducing the overall chiral response. By designing the additive concentration and assembly conditions so that one orientation was selected across a broad area, the team overcame that limitation. Professor Yoon said the work demonstrates a new optical-materials principle in which the rotation direction of light is controlled by molecular arrangement rather than by the complex chemical structure of chiral molecules.

Published in Nature Communications, the study presents the pinwheel array as a route to scalable chiral optical materials based on widely available achiral components. The researchers’ next challenge will be to refine the uniformity, efficiency, and manufacturing compatibility of the structures and to determine how they perform in practical devices. If those obstacles can be addressed, microscopic pinwheels made from ordinary molecules could become a powerful way to program the behavior of light—turning molecular architecture into an optical control switch.

Subject of Research: Structural control of circularly polarized light using microscale chiral pinwheel arrays formed from achiral liquid-crystal molecules.

Article Title: Microchiral pinwheel arrays based on achiral molecules

News Publication Date: 14-Aug-2026

Web References: https://doi.org/10.1038/s41467-026-76089-z

References: Han, Jeong Yeon, et al. “Microchiral pinwheel arrays based on achiral molecules.” Nature Communications. DOI: 10.1038/s41467-026-76089-z.

Image Credits: KAIST

Keywords

Circularly polarized light, chirality, achiral molecules, liquid crystals, pinwheel structures, optical materials, nanofibers, photonics, displays, optical communications, polarization sensors, metamaterials, KAIST

Wang’s research primarily emphasizes the manipulation and control of light at the nanoscale—an area that continues to challenge even the most sophisticated optical systems. By tailoring the behavior of photons with unprecedented precision, his team has achieved remarkable feats in photonic device performance. This involves exploiting novel materials and nanofabrication techniques to engineer optical properties that were once considered impossible to realize.

A notable aspect of Wang’s approach is the integration of artificial intelligence to optimize light-matter interactions. This interdisciplinary synergy accelerates the discovery of new photonic structures by analyzing massive datasets and predicting optimal configurations. The fusion of AI with nanophotonics opens pathways to devices that are not only efficient but also adaptive to changing environmental and operational conditions.

One of the groundbreaking outcomes of Wang’s work is the development of ultra-compact optical components with enhanced functionalities. These include high-sensitivity sensors capable of detecting molecular signatures with exceptional accuracy, potentially revolutionizing fields such as environmental monitoring and medical diagnostics. Moreover, his innovations contribute to the advancement of quantum photonics, where controlling single photons is essential for quantum computing and secure communications.

Wang’s insights extend to improving light-based energy conversion systems. By engineering materials that manipulate light absorption and emission at the nanoscale, his research enhances the efficiency of solar cells and light-emitting devices. This progress directly supports the global push towards sustainable energy solutions, leveraging the fundamental interplay between photons and electrons.

The breadth of Wang’s impact is also evident in fundamental physics. His studies have deepened the understanding of light propagation in complex media, shedding light on phenomena like non-linear optics and topological photonics. These advancements not only enrich scientific knowledge but also lay the groundwork for next-generation technologies such as optical isolators and robust photonic circuits.

As the scientific community continues to explore the boundless possibilities of light, Prof. Zhanshan Wang’s leadership offers a beacon guiding transformative innovations. His relentless pursuit of excellence and collaboration across disciplines underscores the dynamic evolution of photonics, inspiring both researchers and industry alike.

The feature on Prof. Zhanshan Wang in Light: Science & Applications marks a significant acknowledgment of his pioneering role. It encapsulates a journey defined by curiosity, ingenuity, and an unwavering commitment to harnessing light’s power to redefine technological horizons.

Subject of Research:
Nanoscale manipulation and control of light, integration of artificial intelligence in photonics, and development of advanced photonic devices.

Article Title:
Light People: Prof. Zhanshan Wang.

Article References:
Huang, Q., Zhang, R. Light People: Prof. Zhanshan Wang. Light Sci Appl 15, 310 (2026). https://doi.org/10.1038/s41377-026-02387-2

Image Credits: AI Generated

DOI:
https://doi.org/10.1038/s41377-026-02387-2

For decades, the design of metamaterials—particularly metasurfaces whose properties vary spatially to achieve tailored optical responses—has been tethered to iterative parameter tweaking and brute-force computational simulations. Methods like Finite-Difference Time-Domain (FDTD) simulations have been essential in predicting optical behavior but are notorious for their intensive computational demands and scaling challenges. When device dimensions extend into the centimeter scale or beyond, this trial-and-error approach becomes not only onerous but often impractical for timely innovation and commercial viability.

Professor Zhou’s new theoretical framework alleviates these concerns by offering a more analytical and principled approach, derived from the fundamental laws of electromagnetism and wave-matter interaction. By harnessing these rigorous underlying physical principles, his method enables designers to confine the parameter space explored, thereby reducing the enormous computational overhead that plagues traditional simulation techniques. This framework systematically narrows design possibilities, guiding researchers towards optimal configurations with far fewer iterations and less guesswork.

The implications of this development extend beyond mere computational efficiency. The framework bridges the gap between abstract theoretical physics and practical engineering, facilitating designs that are not only precise but also robust against fabrication tolerances and environmental variability. Such robustness is critical for translating metasurface concepts from laboratory curiosities into real-world optical components with scalable production potential.

Furthermore, Professor Zhou emphasizes that this work coincides perfectly with the ascendancy of artificial intelligence (AI) tools, which are increasingly being integrated into scientific research workflows. While AI has already shown promise in accelerating material discovery and device optimization, its synergy with a solid, physics-based theoretical framework could catalyze a revolution in how photonic devices are designed. By constraining the design space through rigorous theory, AI algorithms can operate more efficiently, focusing computational resources on promising regions and potentially uncovering entirely new classes of metasurface functionalities.

This hybrid approach of physics-informed computational design supported by AI heralds a new era of intelligent photonics. It empowers designers to tackle complex, multi-parameter problems that were previously considered intractable or too resource-intensive. As a result, emerging technologies relying on metasurfaces—such as compact lenses, beam shapers, holographic displays, and advanced sensors—may witness accelerated development cycles and enhanced capabilities.

However, the transition to this new design methodology is not without challenges. Compared to widely adopted numerical methods like FDTD, Professor Zhou acknowledges that his theoretical framework initially appears more abstract and mathematically sophisticated, potentially posing a barrier to widespread adoption. Its complexity demands a deeper understanding of electromagnetic theory, which may seem less accessible to engineers and experimentalists accustomed to intuitive, simulation-based workflows.

Recognizing this, the research team is actively engaged in democratizing this approach by developing user-friendly tools, comprehensive tutorials, and open-source software implementations. These educational resources aim to make the sophisticated theory more approachable and integrated into standard photonics design toolkits. The vision is to cultivate a broad community of users who can leverage these advances without being hindered by conceptual or technical difficulties.

The potential for broader impact also resonates with trends in photonics towards miniaturized, multifunctional components. As devices shrink and become more intricate, traditional trial-and-error design scales poorly. Theoretical frameworks that incorporate physical insights enable designers to anticipate emergent behaviors and nonlinear effects that purely numerical methods may overlook or misinterpret. This level of predictive power is essential for engineering next-generation photonic systems that demand high efficiency, low loss, and tailored spectral responses.

Moreover, the framework’s capability to reduce design times aligns well with industrial demands, where time-to-market pressures are relentless. Faster and more precise metasurface design workflows can accelerate prototyping, reduce costs, and foster innovation cycles that keep pace with other rapidly advancing technologies. Industries ranging from telecommunications and augmented reality to medical imaging stand to benefit significantly.

In addition to industrial applications, Professor Zhou’s work opens new avenues in fundamental science. By elucidating the connections between metasurface geometry, material composition, and electromagnetic response from a foundational standpoint, researchers gain deeper insights into wave phenomena and metamaterial physics. These insights could fuel novel discoveries in related fields such as topological photonics, nonlinear optics, and quantum light-matter interactions.

The integration of this theoretical framework with experimental methodologies also represents a fertile ground for cross-disciplinary collaboration. Material scientists, optical engineers, and physicists are encouraged to converge, leveraging collective expertise to push meta-device innovation beyond incremental improvements. This collaborative spirit is crucial for translating theoretical advances into practical devices with transformative properties.

Looking forward, the growing computational power available alongside AI accelerators and quantum-inspired algorithms promises to further synergize with Professor Zhou’s framework. Such computational advancements will expand the tractable complexity of metasurface designs, enabling the exploration of higher-dimensional design spaces and multifunctional objectives. This trajectory points to a future where metasurface design becomes an almost intuitive process, informed by both deep physical understanding and intelligent computational guidance.

In conclusion, Professor Lei Zhou’s theoretical framework signifies a pivotal moment in the history of metamaterial science. By coupling first-principles physics with emerging AI technologies, it promises to lift long-standing design bottlenecks, fostering rapid, efficient, and sophisticated metasurface engineering. As the research community embraces and refines this approach, it is poised to unlock new scientific frontiers and technological breakthroughs that could reshape the optical landscape in the coming decades.

The challenges of making such a complex framework accessible should not be underestimated, but with ongoing efforts to disseminate knowledge and integrate user-friendly tools, an exciting, inclusive era of metasurface research and application is on the horizon. This progress exemplifies how foundational science, when combined with pragmatic innovation, can catalyze transformative impacts in technology and society.

Article References:
Guo, C. Light People: Prof. Lei Zhou spoke about metasurfaces.
Light Sci Appl 14, 231 (2025). https://doi.org/10.1038/s41377-025-01893-z

Image Credits: AI Generated