Abstract
An optical retarder based on the Al nanoslit array was developed. Giant birefringence at near-UV
wavelength was calculated through the finite difference time domain (FDTD) calculation. Quasi Al
nanoslit with subwavelength thickness was fabricated through the electron beam lithography, sputtering
and nanoslit array plasma etching. Retardation from 61 to 80° was measured at the wavelength range
from 380 to 450 nm through the polarization microscopy.
