Polarization Control with Plasmonic Antenna Tips: A Universal Approach to Optical Nanocrystallography and Vector-Field Imaging

Author
Keywords
Abstract
<p>Controlling the propagation and polarization vectors in linear and nonlinear optical spectroscopy enables us to probe the anisotropy of optical responses providing structural symmetry selective contrast in optical imaging. Here, we present a novel tilted antenna-tip approach to control the optical vector-field by breaking the axial symmetry of the nanoprobe in tip-enhanced near-field microscopy. This gives rise to a localized plasmonic antenna effect with significantly enhanced optical field vectors with control of both in-plane and out-of-plane components. We use the resulting vector-field specificity in the symmetry selective nonlinear optical response of second-harmonic generation (SHG) for a generalized approach to optical nanocrystallography and imaging. In tip-enhanced SHG imaging of monolayer MoS<sub>2</sub>\&nbsp;films and single-crystalline ferroelectric YMnO<sub>3</sub>, we reveal nanocrystallographic details of domain boundaries and domain topology with enhanced sensitivity and nanoscale spatial resolution. The approach is applicable to any anisotropic linear and nonlinear optical response and enables the optical nanocrystallographic imaging of molecular or quantum materials.</p>
Year of Publication
2018
Journal
Nano Letters
Volume
18
Number of Pages
2912-2917
Date Published
2018-03
ISSN Number
1530-6984
URL
https://pubs.acs.org/doi/pdf/10.1021/acs.nanolett.8b00108
DOI
10.1021/acs.nanolett.8b00108
JILA PI
Journal Article