A Switchable Mid‐Infrared Plasmonic Perfect Absorber with Multispectral Thermal Imaging Capability

Abstract

A switchable perfect absorber with multispectral thermal imaging capability is presented. Aluminum nanoantenna arrays above a germanium antimony telluride (GST) spacer layer and aluminum mirror provide efficient wavelength-tunable absorption in the mid-infrared. Utilizing the amorphous-to-crystalline phase transition in GST, this device offers switchable absorption with strong reflectance contrast at resonance and large phase-change-induced spectral shifts.

Holographic image generation with a thin-film resonance caused by chalcogenide phase-change material

“…As reported in many previous works using the GST alloy232425262728, GST undergoes a phase change which can be repetitively switched. Because the material characteristics of GST can differ slightly when different composition ratios and sputtering conditions are used23, it was necessary to measure the electrical resistances and optical constants of the actual GST alloy used in this work for amorphous and crystalline states.…”

“…Due to these benefits, GST has not only been used in next-generation non-volatile memory devices2526, but also in upcoming subwavelength-scale display pixels24. Periodic nano-disks patterned on a metal/GST composite layers has been reported for tunable perfect absorbing metamaterials in the visible and mid-infrared ranges2728, and optically reconfigurable metasurfaces based on GST were very recently reported29. However, there are no reports on the full implementation of a digital hologram which can be directly observed by the human eye with a phase-changeable chalcogenide compound.…”

Advances in Full Control of Electromagnetic Waves with Metasurfaces

“…The latter approach has been extensively used for sensing applications. Providentially, various of materials are lined up for active device designs, such as phase change REVIEW materials (PCMs), [173][174][175][176][177][178] 2D materials, [ 179,180 ] liquid crystals, [ 181 ] microelectromechanical systems (MEMSs) [ 182,183 ] and PIN diodes. [ 184 ] The tunable performance can be accomplished via optical, electrical, or mechanical approaches by selecting appropriate active materials.…”

All-dielectric phase-change reconfigurable metasurface

“…1 Phase-change materials, including chalcogenides, [2][3][4][5] vanadium dioxide, [6][7][8] gallium, 9 and liquid crystals, [10][11][12] have featured prominently in this evolution. We now show that the chalcogenides offer a uniquely flexible platform for the realization of non-volatile, optically-switchable alldielectric metamaterials.…”