Heterodyne method for determining the surface tilt angle of nematic liquid-crystal displays

The high-sensitivity pretilt-angle measurement of liquid-crystal displays, based on the modified crystal-rotation configuration and the use of a common-path heterodyne interferometer, is proposed. in this technique, environmental disturbance and surface reflection are eliminated to a large extend, thus providing advantages for both constructing a simple-optics measurement system and achieving fast measurement with high accuracy and sensitivity.