Nanophotonics | |
Electrically tunable metasurface by using InAs in a metal–insulator–metal configuration | |
Sorger Volker J.1  Park Junghyun2  Kim Soo Jin3  Kim Seong Jun3  | |
[1] Department of Electrical and Computer Engineering, George Washington University, Science & Engineering Hall, 800 21st Street, NW, Washington DC20052, USA;Samsung Advanced Institute of Technology, Samsungro 130, Youngtong-gu, Suwon16678, Republic of Korea;School of Electrical Engineering, Korea University, Engineering Building Room 216,145, Anam-ro, Seongbuk-gu, Seoul02841, Republic of Korea; | |
关键词: inas; metasurface; optical modulator; surface plasmonics; wavefront shaping; | |
DOI : 10.1515/nanoph-2021-0618 | |
来源: DOAJ |
【 摘 要 】
The ability of modulating optical properties at a lateral subwavelength scale is of crucial importance due to its potential applications for wide-angle holographic displays, optical communications, and interferometric sensors. Here, we present an electrically tunable metasurface whose optical properties can be element-wise controlled at the lateral subwavelength scale in the mid-infrared wavelength regime. Our proposed device facilitates an n-doped InAs layer as a dynamic-tunable layer, and the charge carrier concentration inside the InAs layer is tailored by external gate biases. This InAs active layer is sandwiched between top aluminum strip antennas and a bottom gold substrate, forming the metal–insulator–metal configuration. The change of the charge carrier concentration gives rise to modulation of the amplitude and phase of reflected light in a mid-infrared regime. Numerical investigations show the reflectivity contrast of 44%P with biases of −2.5–0 V and the phase change of 236° with biases of −15 V to +15 V at the wavelength of ∼5 μm. Versatile wavefront shaping such as beam focusing with Fresnel Zone plate and beam steering with saw-tooth phase grating is also provided.
【 授权许可】
Unknown