Development of a Lens That Controls All Three Characteristics of Light

KAIST Research Team, Multifaceted Applications Including Commercialization of 3D Holograms

Three-dimensional vector hologram implemented through a universal metasurface. (a) Schematic of a universal metasurface that creates different three-dimensional vector holographic images depending on the polarization state of the incident light. (b) Measured holographic image results, where colors represent the polarization state at each point. Adapted with permission. Copyright 2022, WILEY-VCH. / Source = Provided by KAIST

[Asia Economy Reporter Kim Bong-su] Domestic researchers have developed a meta lens capable of simultaneously controlling the three main properties of light?intensity, phase, and polarization. This technology is attracting attention as a means to revolutionize the commercialization of 3D holograms, augmented reality glasses, LIDAR, quantum optics, and optical communications.

The Korea Advanced Institute of Science and Technology (KAIST) announced on the 2nd that Professor Shin Jong-hwa’s research team from the Department of Materials Science and Engineering developed a 'universal metasurface' with such capabilities. The technology to freely control light’s intensity, phase, and polarization with a single device has remained an unsolved challenge in optics since Galileo observed Jupiter’s moons with a telescope, up to the present day where the James Webb Telescope can observe the universe from 13 billion years ago.

Recently, metasurfaces?artificial structures smaller than micrometers arranged along surfaces of conventional materials like glass?have been expected to solve this challenge by enabling highly flexible control of light’s properties. Related research is being competitively conducted worldwide by universities, research institutes, and companies.

These metasurfaces can function as lenses with thicknesses only a few micrometers, which is a thousandth of the thickness of regular glasses. Moreover, they have the potential to simultaneously perform functions of other optical components such as polarizers and color filters. This could significantly reduce the thickness and simplify the manufacturing process of current commercial displays like OLEDs, which require multiple optical films. Additionally, they can be widely applied to new optical components for video holograms, augmented reality (AR) glasses, and LIDAR, making them a versatile technology of great interest.

However, metasurfaces reported so far have only been able to simultaneously control some of the three properties of light for specific colors, leaving the complete control of all three properties with a single device an unresolved challenge.

The research team, inspired by mathematical principles related to matrices, theoretically demonstrated that a dielectric metasurface composed of two closely spaced layers can perfectly control the three main properties of light, and experimentally verified this. Notably, they proposed and successfully implemented vector holograms, which were previously impossible with a single device. Academically, this study is significant as it is the first to show how to realize two independent arbitrary three-dimensional electromagnetic field distributions satisfying Maxwell’s equations through the polarization-selective properties of metasurfaces.

The team theoretically proved that combining the universal metasurface with a conventional lens enables the implementation of any polarization-selective linear optical system. This means that complex mathematical operations or data processing, including Fourier transforms, can be optically realized in a simple manner. As an example, the team demonstrated that a probabilistic quantum CNOT gate array can be created using only the universal metasurface and a lens. This technology is expected to be applicable not only in quantum optics but also in fields such as optical communications and machine learning-based facial recognition using optical neural networks.

The research team stated, "Through this study, we have solved the long-standing challenge in optics of complete control over light’s intensity, phase, and polarization, and theoretically demonstrated the implementation of all polarization-selective linear optical systems. We plan to actively develop applied optical devices that overcome existing limitations by leveraging the potential of metasurfaces."

This research was published on the 3rd of last month in the international journal Advanced Materials.

This content was produced with the assistance of AI translation services.