Glass Imprinting Process for Fabrication of Sub-Wavelength Periodic Structures

Using direct glass imprinting with glassy carbon molds, one-dimensional surface-relief gratings with 500 nm pitch were fabricated on phosphate glasses. The maximum grating height attained in this study was 730 nm, which was formed by pressing at the softening temperature of the glass at a constant pressure of 0.4 kN/cm 2 . A large area pattern 6 × 6 mm 2 with a 350-nm groove depth was also fabricated. Phase retardation of 0.1 λ was attained between transverse electric (TE)- and transverse magnetic (TM)-polarized light in the visible wavelength region. Calculated retardation using a rigorous coupled wave analysis agreed well with the experimental results.