Liquid switchable radial polarization converters made of sculptured thin films

• Published in: Applied surface science 2019-05, Vol.475, p.230-236
• Main Authors: Oliva-Ramírez, Manuel, Rico, Victor J., Gil-Rostra, Jorge, Arteaga, Oriol, Bertran, Enric, Serna, Rosalía, González-Elipe, Agustín R., Yubero, Francisco
• Format: Article
• Language: English
• Subjects: Oblique angle deposition; q-Plates; Radial polarization converters; Sculptured thin films
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2018.12.200

[Display omitted] •Porous nanostructured sculptured multilayer with axisymmetric optical activity.•Wavelength dependent response through multilayer optical design.•Optical activity switchable through liquid infiltration within the pore structure.•To be considered as thin film radial polarization converters. A radial polarization converter is a super-structured optical retarder that converts a conventional linearly polarized light beam into a structured beam with radial or azimuthal polarization. We present a new type of these sophisticated optical elements, which is made of porous nanostructured sculptured single thin films or multilayers prepared by physical vapor deposition at an oblique angle. They are bestowed with an axisymmetric retardation activity (with the fast axis in a radial configuration). In particular, a Bragg microcavity multilayer that exhibits a tunable transmission peak in the visible range with a retardance of up to 0.35 rad has been fabricated using this methodology. Owing to the highly porous structure of this type of thin films and multilayers, their retardance could be switched off by liquid infiltration. These results prove the possibility of developing wavelength dependent (through multilayer optical design) and switchable (through vapor condensation or liquid infiltration within the pore structure) radial polarization converters by means of oblique angle physical vapor deposition.