Design of near-Infrared reconfigurable metalens on Silicon-On-Insulator (SOI) platform with Fabry-Perrot phase shifter
Abstract
A metalens is the artificial surface made of billions of sub-wavelength elements and can bend light like traditional optical lens with significant efficiency and already attracted enormous research interests. However, the focus steering mechanism as an important part of optical system, is still under investigation for metalens. In this work, we describe an optical phased array model with the focalization and beam-steering features with specific phase relationship. To realize the focus-steering function on silicon metalens, the cascaded PIN junction enhanced by Fabry-Perrot cavity as the phase shifter is designed with metalens to provide up to 2 π phase variation. Silicon metalens with a diameter of 43 μm and a focus of 40 μm, at 1.55 um wavelength is verified in FDTD simulation. The results show that 10 μm axial displacement is achieved with a carrier injection of 1019 cm-3 with the efficiency of 44%. At the end, the beam focalization and beam steering mechanism are investigated and analyzed. This focus steering mechanism could be deployed to many attractive near-infrared applications, such as fluorescence microscopy and LIDAR.
- Publication:
-
Optics Communications
- Pub Date:
- September 2019
- DOI:
- 10.1016/j.optcom.2019.04.057
- Bibcode:
- 2019OptCo.446...56G
- Keywords:
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- Metalens;
- Focus tuning;
- NIR