Demonstration of a nearly refractive index-matched diffractive optical element with large fabrication tolerance by a...

Nearly refractive index-matched diffractive optical elements (DOEs) are receiving increasing attention due to large fabrication tolerance. This study presents a nearly refractive index-matched DOEs with a refractive index difference of 0.028. A simple and high-precision microfabrication technology is developed. The fabrication tolerance of DOEs is 117.8 nm for a uniformity deviation of 3.46%, which demonstrates 23 times better fabrication tolerance compared with the other reports.