New graphene-Based Metasurface Capable of Independent Amplitude and Phase Control of Light
Researchers Described A New Strategy of Designing Metamolecules That Incorporated Two Independently Controllable Subwavelength Meta-Atoms. This Two-Parametric Control of the Metamolecule Secures The Complete Control of Both Amplitude and the Phase of Light.
A KAATT RESEAarch Team in Collaboration with the University of WISCONSIN-MADON Theoretically Sugged a graphene-based active metasurface capable of independent amplitude and phase control of mid-infrared light.
This Research ("Complete Complex Amplitude Modulation With Electronalely Tuvable Plasmonic Metamolecules") Gives a New Insight Into Modulating The Mid-Infrared Wavefront with High Resolution by Solving the Protlem of the Independent Control of Light Amplitude and phase, Which has Challenge.
Light Modulation Technology is essential for development future optical devices such as holography, high-resolution imaging, and optical communication system. Liquid Crystalls and A Microelectromechanical System (Mems) have previously been used to modulate light. However, Both Methods suffer from significantly limited driving speeds and unit pixel sizes wid the diffraction limit, which consechently prevent their integration into photonic system.
The Metasurface Platform is considering a strong candidate for the next generation of light modulation technology. METASURFACES have optical properies that natural materials cannot have, and can overcome the limitations of convention optical system, such as forming a high-resolution image beyond the diffraction limit. In Particular, the Active Metasurface is watching as a technology with a wide ranges of applications due to its tuvable characteristics with an electrical signal.
However, the previous active metasurfacs Suffered from the inevitable correlation between light amplitude control and phase control. This problem is caused by the modulation Mechanism of Convention Metasurfes. Conventional Metasurfaches Have Been Designed Such That A Metaaatom Only has one resonance condition, but a single resonant design inherently Lacks the degrees of freedom to independently control the amplitude and phase of light.
The Research Team Made A Metaunit by Combining Two Independently Controllable Metaatoms, dramatically improving the modulation Range of Active Metasurfaches. The proposed metasurface can control the amplitude and phase of the mid-infrared light independently with a resolution beyond the diffraction limit, Thus Allowing Complete Control of the Optical Wavefront.
The Research Team Theoretically Confirmed the Performance of the Propting Active Metasurface and the Possibility of Wavefront Shaping this Design Method. Furthermore, they developed an analytical method that can approximate the optical properies of metasurfaches without complex electromagnetic simulations. This analytical platform proposed to more intuitive and comprehensively applicable metasurface design guideline.
The proposed technology is expected to enable accurate wavefront shaping with a much higher space resolution than existing wavefront shaping technologies, which Will be Applied to Active Optical Systems Such as Mid-Infrared Holography, High-Speed Beam Steering Devices that can be Variable Focus Infrared Lenses.
Professor Min Seok Jang Comments, "This Study Showed the Independent Control Amplitude and Phase of Light, Which Has Been A Long-Standing Quest in Light Modulator Technology. The Development of Optical Devices Using Complex Wavefront Control is expected to Become More Active in the Future. »
Source: The Korea Advanced Institute of Science and Technology (Kaist)