Compact and efficient wire grid reflecting polarizersat 121.6 nm

In this work, two structures of wire grid reflecting polarizers have been proposed and optimized through simulation at the target wavelength of 121.6 nm (H Lyman-alpha), which aims to realize compact and efficient polarizers for measuring the magnetic field vector of the solar corona. Both structures are based on a high reflective patterned Al/MgF2 bi-layer on top of an absorbent substrate, and a layer of MgF2 is sandwiched in the Al gaps to prevent it from being oxidized. Two promising solutions were selected, exhibiting a polarization degree of more than 99.99% and a TE-reflectance over 0.3. Their sensitivity to nanowire parameters has been carried out to evaluate manufacturing feasibility. The angular and spectral performance demonstrated that such polarizers have the large potential to significantly contribute to the future far-ultraviolet (FUV) instruments.