Fabrication of division-of-focal-plane polarizer arrays by electron beam lithography

The division-of-focal-plane (DoFP) polarizer is used to capture polarization information in real time without rotating the polarizer. In this paper, different periods of aluminum nano-wire grids with four different orientations offset by 45° were fabricated using electron beam lithography (EBL) and inductively coupled plasma-reactive ion etching (ICP-RIE). The pitch of each unit was 7.4 μm in a standard square. The transmission intensity measurements of DoFP arrays with different periods were performed to obtain the extinction ratios and transmission ratios which were used to evaluate the performance of grid polarizers.