Sol-gel Barium Titanate Nanohole Array as a Nonlinear Metasurface and a Photonic Crystal
Abstract
The quest of a nonlinear optical material that can be easily nanostructured over a large surface area is still ongoing. Here, we demonstrate a nanoimprinted nonlinear barium titanate 2D nanohole array that shows optical properties of a 2D photonic crystal and metasurface, depending on the direction of the optical axis. The challenge of nanostructuring the inert metal-oxide is resolved by direct soft nanoimprint lithography with sol-gel derived barium titanate enabling critical dimensions of 120 nm with aspect ratios of 5. The nanohole array exhibits a photonic bandgap in the infrared range when probed along the slab axis while lattice resonant states are observed in out-of-plane transmission configuration. The enhanced light-matter interaction from the resonant structure enables to increase the second-harmonic generation in the near-UV by a factor of 18 illustrating the potential in the flexible fabrication technique for barium titanate photonic devices.
Keywords
Cite
@article{arxiv.2307.11626,
title = {Sol-gel Barium Titanate Nanohole Array as a Nonlinear Metasurface and a Photonic Crystal},
author = {Ülle-Linda Talts and Helena C. Weigand and Grégoire Saerens and Peter Benedek and Joel Winiger and Vanessa Wood and Jürg Leuthold and Viola Vogler-Neuling and Rachel Grange},
journal= {arXiv preprint arXiv:2307.11626},
year = {2023}
}