A Review of Sub-Wavelength Wire Grid Polarizers and Their Development Trends

There has been a significant rise in the fabrication of polarizing elements with the rapid advancement of polarization imaging technology, coinciding with a rise in research on such elements. This article provides a comprehensive review of sub-wavelength wire grid polarizers which can be applied in different operating wavelength ranges, specifically focusing on their design, as well as their related fabrication processes and metrology methods. First, structural parameters, designed and simulated via the finite-difference time-domain (FDTD) method or rigorous coupled wave analysis (RCWA), and their impact on wire grid performance are investigated based on the effective medium theory. Second, a comprehensive overview of domestic and international studies is provided, focusing on the developments in sub-wavelength wire grid polarizers with single-layer structures and bilayer structures at different operating wavelength bands—deep ultraviolet, visible, middle- and far-infrared, and terahertz wavelength bands. Research related to polarizers with multilayer structures, simulated and carried out via the use of specific software, is also presented. Finally, the progress regarding sub-wavelength wire grid polarizer research is summarized, and future prospects are forecasted, with emphasis on material selection, wire grid structure optimization, and innovation in manufacturing processes.