He joined CSIR-CSIO as Director on 27 July 2020 on lien from IIT Kanpur.
Current research interests include technological applications of metamaterials and plasmonics. His publications and citations may be found on his Google profile page https://scholar.google.co.in/citations?user=tebIaWQAAAAJ&hl=en
Prof. Ramakrishna has worked in the area of metamaterials and plasmonic nanostructured materials and has published over 115 papers in refereed international journals, about 70 papers in conferences and a research monograph entitled “Physics and Applications of Negative Refractive Index Materials”. His works on metamaterials and plasmonics have drawn enormous attention from the scientific community and have been highly cited. He has proposed, for the first time, several new concepts such as: the use of amplifying media in metamaterials and plasmonic structures, the first use of transformation optics to negative index materials, first design for optical frequency metamaterials, first demonstration of negative refraction in acoustic metamaterials, a proper explanation of the choice of the negative root for the wave vector in negative index media coherent control of metamaterials by atomic / molecular resonances, anisotropic metamaterial fibers and so on. His work on the traversal times for light in dispersive media has also been important in understanding light propagation in dispersive media. Among the work in the past 10 years, his papers on perfectly absorbing metamaterials as highly impedance matched antennas at microwave, infra-red and optical frequencies has drawn much attention. His work on actively switchable and nonlinear metamaterial absorbers using phase change materials like vanadium dioxide and nonlinear materials have been widely appreciated in the field. He has pioneered the use of structured indium tin oxide thin films for developing infra-red and microwave metamaterials that have optical transparency for defence applications in vehicle windshields and aircraft canopies. His work on optical properties of plasmonic nanostructures and their use for surface enhanced Raman scattering (SERS) has also drawn attention. Particularly, the first demonstration of broadband extraordinary transmittance in plasmonic systems was shown to occur in highly singular checkerboard plasmonic structures. His works on enhanced visualization of aged latent fingermark by depositing columnar thin films or multilayer gold-dielectric thin films and fluorescent dyes have made it possible to examine rough metallic surfaces for fingermarks. He has brought in insights of interference from thin films to maximize fringe contrast for possibly the first time in this field. His scholarship on metamaterials and plasmonics is widely recognised, with his comprehensive review in 2005 and subsequently his book in 2009 on negative refractive index materials. Prof. Ramakrishna has recently been focussing on the implementation of metamaterials into real-life applications. He has worked on several projects of the defence agencies on various applications including Radar stealth and infra-red camouflage. Expertise in a variety of areas, such as, nano- and micro- structuring of non-conventional materials like polymers, ceramics and metals, thin film deposition techniques and electromagnetic computer simulations has been developed. With a view to technology transfer, techniques such as excimer laser micromachining, imprint lithography, shadow mask deposition and chemical structuring processes are being developed for rapid prototyping and large-scale manufacturing of such structured materials.
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