Fabrication of sub-wavelength periodic structures upon high-refractive-index glasses by precision glass molding

Abstract

One-dimensional surface-relief gratings were fabricated using a direct imprinting process with a glassy carbon (GC) mold at the softening temperatures of oxide glasses. The maximum grating height attained in this study was 730 nm when the grating period was 500 nm, which could be formed by the pressing at the softening temperature of glass under constant pressure of 0.4 kN/cm². A large area glass imprinting was attempted using a GC mold with a periodic patterned area of 6 mm x 6 mm, which has the period of 500 nm and groove depth of 350 nm, respectively. Phase retardation of 0.1 λ was recognized between TE-polarized and TM-polarized lights at 600 nm wavelength. The measured values were in excellent agreement with those calculated using a rigorous coupled wave analysis.