Programmed Achromatic and Wide Field-of-View Retarder Using Form Birefringence of Template-Grown ZnO nanostructures

Achromatic retarders with a wide field of view (FOV) can maintain a consistent performance across a broad range of wavelengths and wide viewing angles. Despite the widespread use of retarders, achieving a true achromatic retarder with a wide FOV remains challenging. Here, we present an achromatic quarter-wave plate (QWP) based on form birefringence (FB) of nanostructures operating in visible wavelengths from 450 to 650 nm. Our 1.8-μm-thick QWP was fabricated using a templated growth method that combines laser interference lithography and hydrothermal growth methods. A flat reflectance spectrum with an average reflectance of 1.37% was measured from the antireflection of a circular polarizer with the FB retarder, confirming the wideband efficiency of the QWP. The achromaticity of retardation was unchanged at greater incident angles.