Linear polarization-separating metalens at long-wavelength infrared.

We designed and fabricated a linear polarization-separation metalens (PSM) made of single-crystal silicon (sc-Si) for long-wavelength infrared (LWIR) imaging. The PSM comprises sc-Si dielectric waveguide pillar meta-atoms with rectangular cross-sections, providing a full 2π phase delay range for two orthogonal linear polarization components with high transmittances (>70%). Electron beam lithography and deep reactive ion etching were used to fabricate the PSM.