”Broadband plasmonics in the optical and THz range” by Prof. Venu Gopal Achanta, Tata Inst of Fundamental Research, Mumbai

Broadband plasmonics in the optical and THz range

Venu Gopal Achanta

DCMP&MS, Tata Institute of Fundamental Research, Mumbai, India

Periodic metal-dielectric structures, plasmonic crystals, are designed for specific studies and need to be redesigned for different materials or scaled for different wavelength regions. This limits their application in modulating the material properties. In order to extend plasmonics to wider materials, it would help to have metamaterials with near-dispersionless response over broadband. Plasmonic quasicrystals offer such broadband, dispersionless response. In this talk, I will present plasmonic quasicrystals in the visible and near infrared wavelength ranges. After discussing their linear and nonlinear optical properties as well as interesting near-field response, some of their applications like beam shift of wavepackets, magneto-plasmonics over multiple bands, and others will be presented. Another way to design broadband metamaterials is to design multi-element structures. I will present one such broadband near perfect absorber with 99.36% absorption in the visible to near infrared region.

In the 2^nd half of the talk, I will present results on THz plasmonic metamaterials. Fano resonances are well studied in a wide variety of structures. Plasmon induced transparency in metamaterials is shown to result in Fano lineshapes. We demonstrated quadrupole-quadrupole interactions as a new paradigm to control the Q factor of Fano resonance.

Bio: Venu Gopal Achanta obtained Ph.D. (Physics) from Tata Institute of Fundamental Research, Mumbai. He subsequently obtained his Ph.D.(Electronics) from Tokyo University. He worked as a NEDO Fellow at FESTA Laboratories, Tsukuba and then as a JST Fellow in the Quantum Information Technology Group, NEC Corporation, Tsukuba during 2000 and 2004. He is a faculty at Tata Institute of Fundamental Research, Mumbai from end of 2004 where he is an Associate Professor currently. His research interest is in planar integrated circuits for quantum information processing. He has more than 100 research publications. He is a senior member of IEEE and member of OSA. He is a Photonics working group member of BRICS nations as well as Indian coordinator of Global Nanophotonics initiative.