Millimeter-wave transmission properties of nematic liquid-crystal cells with a grating-patterned electrode structure

Nematic liquid-crystal (LC) cells with a grating-patterned electrode struct ure such as that used in the visible wavelength region are fabricated and i nvestigated experimentally in the millimeter-wave region. The millimeter-wa ve transmission properties of the LC cells are measured at 50 GHz with resp ect to the applied voltage, molecular orientations and polarization directi ons of the wave. The transmittances of the LC cells for the polarization di rection parallel and perpendicular to the grating vector are about 70-80% a nd 7-8%, respectively. Changes in the transmission induced by the reorienta tion of LC molecules by applying a voltage to the LC cell are observed. It is confirmed that the transmission change in the LC cell is mainly dependen t on the anisotropy of the permittivity of LC materials. The LC cell with r elatively large thickness may be applicable in this wavelength region.