Active-Tuning and Polarization-Independent Absorber and Sensor in the Infrared Region Based on the Phase Change Material of Ge2Sb2Te5 (GST)

Abstract

Phase-change materials (PCMs), possessing thermo-optic and thermo-electric properties, have constantly enabled the rewritable optical data storage and the commercialized phase-change memory devices. In particular, Ge2Sb2Te5 (GST) has been considered for configurable photonics applications, such as active dielectric metasurface. In this paper, we report an active absorber with metal-insulator-metal (MIM) scheme with GST in the infrared region. The absorber consists of Al disk and reflective Al film with a GST spacer layer. Extraordinary absorption with peaks of more than 90% can be achieved over a broad bandwidth, attributing to highly confined gap surface plasmon resonance. In addition, the absorption can be tuned via adjusting the proportion of GST crystallization, which is a unique advantage to design active device. Meanwhile, the absorption is polarization-independent owing to its structural symmetry. Furthermore, we introduce the designed absorber to the application of sensing. This nearly perfect absorbing strategy offers great potential in sensing applications due to its flexibility and polarization-independence.

A Review of Germanium-Antimony-Telluride Phase Change Materials for Non-Volatile Memories and Optical Modulators

“…Another limitation is that conventional metasurfaces-based devices are not cost-effective since once a device is made, it only works for a certain functionality and wavelength. Therefore, there has been considerable interest recently in developing tunable all-dielectric metasurfaces for light modulation applications by using the phase change materials [94][95][96][97] instead of metallic elements used in earlier works.…”

A Broadband Polarized Metamaterial Absorber Driven by Strong Insensitivity and Proximity Effects

“…The design specifications vary for different applications including single-, dual-, and multi-band as well as broadband frequency performance. The significant advantages of the proposed absorber structure lie in polarization insensitivity, wide incident angle, near-perfect absorption, large bandwidth, and single to multi-band operation [7]. There are several drawbacks to conventional absorbers.…”

Dual-Functional Nanoscale Devices Using Phase-Change Materials: A Reconfigurable Perfect Absorber with Nonvolatile Resistance-Change Memory Characteristics

“…Use of phase-change materials (PCMs) in electrical and optical systems has introduced widespread applications, including uses in optical data storage [1][2][3] and photonic nanodevices [4,5]. Attributes of PCMs include nonvolatile phase changes, rapid switching, and quick responses to stimuli, reasonable data retention, and long-term stability [6][7][8].…”