Design of practicable phase-change metadevices for near-infrared absorber and modulator applications

Santiago García-Cuevas Carrillo, Geoffrey R. Nash, Hasan Hayat, Martin J. Cryan, Maciej Klemm, Harish Bhaskaran, C. David Wright
2016 Optics Express  
Phase-change chalcogenide alloys, such as Ge 2 Sb 2 Te 5 (GST), have very different optical properties in their amorphous and crystalline phases. The fact that such alloys can be switched, optically or electrically, between such phases rapidly and repeatedly means that they have much potential for applications as tunable photonic devices. Here we incorporate chalcogenide phase-change films into a metal-dielectric-metal metamaterial electromagnetic absorber structure and design absorbers and
more » ... lators for operation at technologically important near-infrared wavelengths, specifically 1550 nm. Our design not only exhibits excellent performance (e.g. a modulation depth of ~77% and an extinction ratio of ~20 dB) but also includes a suitable means for protecting the GST layer from environmental oxidation and is well-suited, as confirmed by electrothermal and phase-transformation simulations, to in situ electrical switching. We also present a systematic study of design optimization, including the effects of expected manufacturing tolerances on device performance and, by means of a sensitivity analysis, identify the most critical design parameters.
doi:10.1364/oe.24.013563 pmid:27410372 fatcat:3dcxyftmrfhrlpotvzrntbcg2m