Switchable circular beam deflectors
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2016-03-21 |
| Journal | Journal of Physics D Applied Physics |
| Authors | Xiaobing Shang, Pankaj Joshi, Jin-Yi Tan, Jelle De Smet, Dieter Cuypers |
| Institutions | Ghent University, Vrije Universiteit Brussel |
| Citations | 2 |
Abstract
Section titled āAbstractāIn this work, we report two types of electrically tunable photonic devices with circularly symmetric polarization independent beam steering performance (beam condensing resp. beam broadening). The devices consist of circular micro grating structures combined with\nnematic liquid crystal (LC) layers with anti-parallel alignment. A single beam deflector converts a polarized and monochromatic green laser beam ( = 543.5 nm) into a diffraction pattern, with the peak intensity appearing at the third order when 0Vpp is applied and at the zeroth order (no deflection) for voltages above 30Vpp. Depending on the shape of the grating structure (non-inverted or inverted), the deflection is inwards or outwards. Both grating types can be made starting from the same diamond-tooled master mold. A polarized white\nlight beam is symmetrically condensed resp. broadened over 2Ā° in the off state and is passed through unchanged in the on state. By stacking two such devices with mutually orthogonal LC alignment layers, polarization independent switchable circular beam deflectors are realized with a high transmittance (>80%), and with the same beam steering performance as the polarization dependent single devices.