Fabrications of liquid-crystal polarization converters and their applications

This study presents a simple but accurate method for measuring the helical twisting power of chiral doped liquid crystals using axially symmetrical photo-alignment in azo dye-doped liquid crystal films. As reported in our previous paper1, the discontinuous twisting effect produces a disclination line in photo-aligned axially symmetrical liquid crystal films, which can be applied for use as a polarization converter. The pitch and helical twisting power can be obtained by measuring the rotation angle of the disclination line in chrial doped liquid crystal. This method is independent of cell gap and provides an error below 0.5%.