Measurement of Pretilt Angle

Inside the liquid crystal, the refractive indices for the x and y components are and Uy, respectively. There is a double refraction at the air-liquid crystal interface the refraction angles for the components are and i/fy, respectively, which are calculated by 

On the exit plane the e-beam and o-beam are separated by the distance given by 

The first term on the right side of the above equation is 

---

M.-P. Cuminal and M. Brunet, A technique for measurement of pretilt angles arising from alignment layers, Liq. Cryst., 22, 185 (1997). 

---