Large optical nonlinearity of nanoantennas coupled to an epsilon-near-zero material
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Supplementary Information
Date
2018-01-26
Authors
Alam, M. Zahirul
Schulz, Sebastian A.
Upham, Jeremy
De Leon, Israel
Boyd, Robert W.
Journal Title
Journal ISSN
Volume Title
Publisher
Springer Nature
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Abstract
The size and operating energy of a nonlinear optical device are fundamentally constrained by the weakness of the nonlinear optical response of common materials. Here, we report that a 50-nm-thick optical metasurface made of optical dipole antennas coupled to an epsilon-near-zero material exhibits a broadband (∼400 nm bandwidth) and ultrafast (recovery time less than 1 ps) intensity-dependent refractive index n2 as large as −3.73 ± 0.56 cm2 GW−1. Furthermore, the metasurface exhibits a maximum optically induced refractive index change of ±2.5 over a spectral range of ∼200 nm. The inclusion of low-Q nanoantennas on an epsilon-near-zero thin film not only allows the design of a metasurface with an unprecedentedly large nonlinear optical response, but also offers the flexibility to tailor the sign of the response. Our technique removes a longstanding obstacle in nonlinear optics: the lack of materials with an ultrafast nonlinear contribution to refractive index on the order of unity. It consequently offers the possibility to design low-power nonlinear nano-optical devices with orders-of-magnitude smaller footprints.
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Keywords
Low-power nonlinear nano-optical devices , Nonlinear optical device , Optical dipole antennas coupled to an epsilon-near-zero material
Citation
Alam, M.Z., Schulz, S.A., Upham, J. et al. (2018) 'Large optical nonlinearity of nanoantennas coupled to an epsilon-near-zero material', Nature Photonics, 12, pp. 79–83. https://doi.org/10.1038/s41566-017-0089-9
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© 2018, Springer Nature Limited. This is a post-peer-review, pre-copyedit version of an article published in Nature Photonics. The final authenticated version is available online at: https://doi.org/10.1038/s41566-017-0089-9