| Author | Zografopoulos D.C. |
| Author | Sinatkas G. |
| Author | Lotfi E. |
| Author | Shahada L.A. |
| Author | Swillam M.A. |
| Author | Kriezis E.E. |
| Author | Beccherelli R. |
| Available date | 2020-02-05T08:53:07Z |
| Publication Date | 2018 |
| Publication Name | Applied Physics A: Materials Science and Processing |
| Resource | Scopus |
| ISSN | 9478396 |
| URI | http://dx.doi.org/10.1007/s00339-017-1506-0 |
| URI | http://hdl.handle.net/10576/12727 |
| Abstract | A class of electro-optically tunable metamaterial absorbers is designed and theoretically investigated in the infrared regime towards realizing free-space amplitude modulators. The spacer between a subwavelength metallic stripe grating and a back metal reflector is occupied by a bilayer of indium tin oxide (ITO) and hafnium oxide (HfO 2). The application of a bias voltage across the bilayer induces free-carrier accumulation at the HfO 2/ITO interface that locally modulates the ITO permittivity and drastically modifies the optical response of the absorber owing to the induced epsilon-near-zero (ENZ) effect. The carrier distribution and dynamics are solved via the drift-diffusion model, which is coupled with optical wave propagation studies in a common finite-element method platform. Optimized structures are derived that enable the amplitude modulation of the reflected wave with moderate insertion losses, theoretically infinite extinction ratio, sub-picosecond switching times and low operating voltages. 2018, Springer-Verlag GmbH Germany, part of Springer Nature. |
| Sponsor | This report was made possible by a NPRP award [NPRP 7-456-1-085] from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the authors. |
| Language | en |
| Publisher | Springer Verlag |
| Title | Amplitude modulation in infrared metamaterial absorbers based on electro-optically tunable conducting oxides |
| Type | Article |
| Pagination | - |
| Issue Number | 2 |
| Volume Number | 124 |
