Fabrication of single‐layer metallic nano‐gratings as polarisers by the combination of nanoimprint lithography and lift‐off method

Abstract

To explore the application of miniaturised polarisers into the detection of the skylight polarisation angle, a fabrication process for single-layer metallic nano-gratings, which was treated as polarisers in the polarised light testing instrument, was proposed. With the help of the combination of two efficient fabrication methods, the nanoimprint lithography and the lift-off method, different directions of the metallic gratings with 200 nm period, 110 nm linewidth and 60 nm height were fabricated simultaneously on the substrate. An interval ultrasound method is proposed to avoid grating structure damage during the lift-off process. Additionally, the effect of the SiO2 layer addition during the etching process on the transmission performance of metallic gratings is presented by a brief theory analysis and experiment results. The fabricated grating is installed on the designed testing instrument to measure the angle of polarised light and the final angle output error is within ±0.25°, which demonstrates that the fabricated metallic gratings have a good prospect as a polaroid applied in the polarisation navigation.