In-Depth Analysis of Polarizer Gratings with Sub-Wavelength Structures

Ultra-sparse nanowire grids – grating structures consisting of periodic dielectric wires with a cross section much smaller than the used wavelength – exhibit strong polarization dependencies over a wide range of wavelengths. These characteristics make them a viable choice as nanostructured polarizers for optical systems, where compact integrability and  thermal stability are critical, and this approach has distinct advantages over its conventionally used counterparts based on birefringent crystals or multilayer systems.

In this week’s newsletter we perform a detailed analysis of such a structure in the fast physical optics modeling and design software VirtualLab Fusion, using the work of [J. W. Yoon et al., Opt. Express 23, 28849-28856 (2015)] as a reference. In this example, we not only calculate the polarization-dependent efficiencies of the light reflected and transmitted by the periodic structure, but also visualize how the field propagates inside, clearly illustrating the polarizing behavior of the nanowire arrangement: The TM-polarized part travels through practically unaffected, while the TE-polarized component is almost completely reflected.

This analysis is enabled by VirtualLab Fusion’s Field Inside Component Analyzer: FMM. You can also find a detailed guide to this at the links below.