Open AccessBroadband ultrathin circular polarizer at visible and near-infrared wavelengths using a non-resonant characteristic in helically stacked nano-gratings
Author(s) -
Jeong-Geun Yun,
Sun-Je Kim,
Hansik Yun,
Kyookeun Lee,
Jaeyong Sung,
Joon-Soo Kim,
Yohan Lee,
Byoungho Lee
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.014260
Subject(s) - polarizer , optics , materials science , extinction ratio , grating , optoelectronics , wavelength , visible spectrum , polarization (electrochemistry) , broadband , circular polarization , rigorous coupled wave analysis , diffraction grating , physics , chemistry , birefringence , microstrip
Modern imaging and spectroscopy systems require to implement diverse functionalities with thin thickness and wide wavelength ranges. In order to meet this demand, polarization-resolved imaging has been widely investigated with integrated circular polarizers. However, the circular polarizers which operate at the entire visible wavelengths and have a thickness of several tens of nanometers have not been developed yet. Here, a circular polarizer, operating at the entire visible wavelength range, is demonstrated using helically stacked aluminum nano-grating layers. High extinction ratio and broad operation bandwidth are simultaneously achieved by using non-resonant anisotropic characteristics of the nano-grating. It is theoretically verified that the averaged extinction ratio becomes up to 8 over the entire visible wavelength range while having a thickness of 390 nm. Also, the feasibility of the proposed structure and circular polarization selectivity at the visible wavelength range are experimentally verified. It is expected that the proposed structure will lead to extreme miniaturization of a circular polarizer and contribute greatly to the development of mobile/wearable imaging systems such as virtual reality and augmented reality displays.