POLARIZATION ROTATOR AND OPTICAL DEVICE

摘要

The present invention provides a polarization rotator and an optical device. The polarization rotator includes a first twisted nematic liquid crystal which has an angle of R/2 between the direction of a liquid crystal director on one surface thereof and the direction of a liquid crystal director on the other surface thereof; and a second twisted nematic liquid crystal which is arranged on the first twisted nematic liquid crystal and allows the direction of a liquid crystal director on one surface thereof to have an angle of R/2 + 90 degrees based on the direction of the liquid crystal director on the one surface of the first twisted nematic liquid crystal and allows a director on the other surface thereof to have R+ 90 degrees. So, polarization rotation with a constant angle can be provided.