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Powerful Bragg reflector with metamaterial

Ultrahigh refractive index metamaterial made by gold nanospheres

05.10.2022 - Mirror-based device only reflects desired light.

Mirrors are used not only in daily life but also in cutting-edge technologies such as semi­conductor processing and high-resolution displays. Recently, a powerful Bragg reflection mirror based on high-index meta­materials has been developed that only reflects desired light. A research team led by Gi-Ra Yi at Pohang University of Science & Techno­logy (Postech) with the research team led by Seok Joon Kwon and Pil Jin Yoo at Sung­kyunkwan University have together developed an ultrahigh refractive index meta­material by closely packing gold nano­spheres and a reflector that combines the meta­material with a polymer.

Meta­materials – with properties that do not exist in nature – can be designed to have a negative or ultrahigh refractive index. However, meta­materials with a high refractive index still have limita­tions from designing to manufacturing. To overcome this issue, the research team developed a meta­material that is uniformly arranged with the 1-nano­meter-level gaps by assembling spherical gold nano­particles.

This material, which maximizes light-matter inter­action, recorded the highest refractive index in the visible and near-infrared regions. The 2D super­structures exhibited the highest-ever refrac­tive index of 7.8. The distributed Bragg reflector (DBR), which is made by stacking these meta­materials and polymer layers with a low refractive index, strongly reflected specific wavelengths.

Further­more, the research team established the theory of a plasmonic perco­lation model that can explain the extremely high refractive index. As it theo­retically explains the ultrahigh refractive index of metamaterials that could not be explained in previous studies, the develop­ment of related research fields is anticipated in the future. This study is also garnering attention from academic circles and industry for its applica­bility in precise semi­conductor processes and high-resolution displays. (Source: Postech)

Reference: D.-I. Shin et al.: Percolated Plasmonic Superlattices of Nanospheres with 1 nm-Level Gap as High-Index Metamaterials, Adv. Mat. 34, 2203942 (2022); DOI: 10.1002/adma.202203942

Link: Dept. of Chemical Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea

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Welding with Civan's Ultrafast CBC-Laser: Basics, Opportunities and Challenges

The first part of the webinar will provide an overview of the fundamentals and challenges of the welding process and the features of the CIVAN CBC laser. The second part of the webinar will discuss approaches to take advantage of fast, arbitrary beam shaping to control process problems.

Register now

Digital tools or software can ease your life as a photonics professional by either helping you with your system design or during the manufacturing process or when purchasing components. Check out our compilation:

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