Abstract-Permanently reconfigured metamaterials due to terahertz induced mass transfer of gold

Permanently reconfigured metamaterials due to terahertz induced mass transfer of gold Andrew C. Strikwerda, Maksim Zalkovskij, Krzysztof Iwaszczuk, Dennis Lund Lorenzen, and Peter Uhd Jepsen  »View Author Affiliations

Optics Express, Vol. 23, Issue 9, pp. 11586-11599 (2015)
http://dx.doi.org/10.1364/OE.23.011586

http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-23-9-11586

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Abstract

We present a new technique for permanent metamaterial reconfiguration via optically induced mass transfer of gold. This mass transfer, which can be explained by field-emission induced electromigration, causes a geometric change in the metamaterial sample. Since a metamaterial’s electromagnetic response is dictated by its geometry, this structural change massively alters the metamaterial’s behavior. We show this by optically forming a conducting pathway between two closely spaced dipole antennas, thereby changing the resonance frequency by a factor of two. After discussing the physics of the process, we conclude by presenting an optical fuse that can be used as a sacrificial element to protect sensitive components, demonstrating the applicability of optically induced mass transfer for device design.

© 2015 Optical Society of America

Abstract-Metamaterial composite bandpass filter with an ultra-broadband rejection bandwidth of up to 240 terahertz

Andrew C. Strikwerda^1,a), Maksim Zalkovskij¹, Dennis Lund Lorenzen¹,

Alexander Krabbe¹, Andrei V. Lavrinenko¹ and Peter Uhd Jepsen¹


1 DTU Fotonik—Department of Photonics Engineering, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
a) Author to whom correspondence should be addressed. Electronic mail: astr@fotonik.dtu.dk.
Appl. Phys. Lett. 104, 191103 (2014); http://dx.doi.org/10.1063/1.4875795

http://scitation.aip.org/content/aip/journal/apl/104/19/10.1063/1.4875795

We present a metamaterial, consisting of a cross structure and a metal mesh filter, that forms a composite with greater functional bandwidth than any terahertz (THz) metamaterial to date.Metamaterials traditionally have a narrow usable bandwidth that is much smaller than commonTHz sources, such as photoconductive antennas and difference frequency generation. The composite structure shown here expands the usable bandwidth to exceed that of current THz sources. To highlight the applicability of this combination, we demonstrate a series ofbandpass filters with only a single pass band, with a central frequency (f0 ) that is scalable from 0.86–8.51 THz, that highly extinguishes other frequencies up to >240 THz. The performance of these filters is demonstrated in experiment, using both air biased coherent detection and a Fourier transform infrared spectrometer (FTIR), as well as in simulation. We present equations—and discuss their scaling laws—which detail the f0 and full width at half max (Δf) of the pass band, as well as the required geometric dimensions for their fabrication using standard UVphotolithography and easily achievable fabrication linewidths. With these equations, the geometric parameters and Δf for a desired frequency can be quickly calculated. Using thesebandpass filters as a proof of principle, we believe that this metamaterial composite provides the key for ultra-broadband metamaterial design.