Electrically reconfigurable nonvolatile flatband absorbers in the mid-infrared with wide spectral tuning range

TL;DR

This paper demonstrates an electrically switchable, nonvolatile plasmonic metasurface for mid-infrared absorption with wide spectral tuning, angle independence, and low power operation, advancing reconfigurable infrared photonics.

Contribution

It introduces a novel Ge2Sb2Te5-based metasurface enabling in-situ electrical control of infrared absorption without continuous power, with deep subwavelength localization and flatband behavior.

Findings

Achieved 3-5 microns wavelength tunability

Demonstrated zero static power operation

Reversible switching over 26 cycles

Abstract

While recent advances in reconfigurable photonics have provided new avenues for manipulating light on the subwavelength scale, on-demand control of infrared absorption remains elusive. Here, we experimentally demonstrate a plasmonic metasurface based on the phase change material Ge2Sb2Te5 with in-situ electrically-switchable infrared absorption in the 3-5 microns wavelength range. Unlike traditional infrared microstructures based on volatile phase change materials, our device does not require the external stimuli to be continuously applied in order to maintain a given optical state, thus enabling zero static power operation. Furthermore, the 400x deep-subwavelength field localization supported by our device not only allows robust tuning of its spectral response but also makes its absorptivity independent of the angle of incidence, thus enabling a flatband behavior. We conduct switching of our device using rapid thermal annealing and reversible switching using electrical pulses over 26 cycles. Our device provides new avenues for infrared absorption control and serves as a steppingstone for the next generation of mid-wave infrared photonics.