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OSA Student Chapter Meeting

SPEAKER:Jizhou Wang
TITLE:Microcavity Nonlinear Optics with an Organically Functionalized Surface

This paper reports enhanced optical nonlinear effects at the surface of an ultrahigh-Q silica microcavity functionalized by a thin layer of organic molecules. The maximal conversion efficiency of the third-harmonic generation reaches approximately 4 orders of magnitude higher than that in a reported silica microcavity.

SPEAKER:Mariia Shutova
TITLE: Plasmonic nanostructures for subwavelength focusing of light with twisted wavefront
The ability of plasmonic antennas to concentrate laser light into subwavelength volumes promoted the imaging of biological structures with super-resolution. However, the confinement of unstructured optical fields within a small volume is insufficient for studies of such phenomena as chirality in biomolecules. The confined field must also be structured to have specific properties. Structured light with twisted wavefront carries OAM, has corkscrew wavefront with the phase singularity at the center, where intensity equals zero. This light is left- or right handed in the same sense as some biological molecules. Left-/right-handed molecules are known as chiral. Modern research suggests possible interaction between "chiral" light and chiral molecules. To detect the impact of the structural "twist" on the chiral molecule, the twist feature size (the diameter of the dark spot at the center) needs to be comparable with the size of the molecule (~nm). However, an optical diffraction limit does not allow us to achieve such small spot sizes. A plasmonic antenna confining the spatial structure of light inside the small volume can solve this problem. We use focused ion beam microscopy to manufacture such a nanoantenna and build an experimental setup, that is capable of detecting optical field structure on nanoscale. I will present progress report on this work and show the most recent results.

Thursday, October 31 2019
IQSE 578, 12:30
Mitchell Physics Building

Department of Physics and Astronomy
Institute for Quantum Science and Engineering
Texas A&M University

(Pizza lunch as usual. Newcomers welcome!)

Host: Aysan Bahari