On Optical Antennas, Quantum Emitters and Biological Nanoparticles: Understanding and Exploiting Efficient Light-Matter Interaction

Seminar | April 7 | 2-3 p.m. | 277 Cory Hall

Speaker/Performer:  Prof. Vahid Sandoghdar, Max Planck Institute for the Science of Light

Sponsor:  Berkeley Nanosciences and Nanoengineering Institute

Light-matter interaction at the nanometer scale lies at the heart of elementary optical processes such as absorption, emission, or scattering. In this presentation, we shall consider the intrinsic scattering cross section of a nano-object and discuss 1) its implications for sensitive fluorescence-free detection, and 2) ways to enhance the optical response of a nano-object by using antennas.

Nearly two decades ago, we showed that single gold nanoparticles as small as 5 nm could be detected via interferometric detection of their scattering, giving birth to a scheme that was later coined iSCAT. Since then, it has been shown that unlabeled nano-objects as small as viruses, vesicles, or proteins can be detected, counted, and tracked.

In this presentation, we discuss the use of machine learning for pushing the detection sensitivity of iSCAT to protein mass below 10 kDa. Moreover, we introduce a new method for characterizing the size and refractive index of nanoparticles based on interferometric nanoparticle tracking analysis (iNTA). Furthermore, we consider an optofluidic antenna for improving photon counts and observation times in sensitive single-molecule fluorescence studies.

In addition, we will present a new near-field scanning technique for optimal coupling of plasmonic nanoantennas, and demonstrate strong coupling on single semiconductor quantum dots at room temperature.
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Vahid Sandoghdar is director of the nano-optics division of the MPI Light. He did his PhD at Yale and postdoc at École Normale Paris. After some years at ETH Zurich he joined MPI in 2011. Founder of the MPZ für Physik und Medizin, a joint research center that aims to address questions in fundamental medical research with physical and mathematical methods. He is a visiting Miller Prof this spring.

Event Contact:  victorr@eecs.berkeley.edu, 510-643-6681

Access Coordinator:  Avi Rosenzweig,  victorr@eecs.berkeley.edu,  510-643-6681