The refractive index of the polymer n p is adjusted relative to the ordinary refractive index of dispersed droplets of nematic liquid crystal n o to regulate the angle of maximum transmission through a film in the presence of an applied field. Maximum transmission occurs at normal incidence when n p ≤n o with the breadth of the angle of view being largest at n p =n o . When np >n o , maximum transmission is peaked at an angle away from normal incidence, the value of the angle depending upon the ratio n p /n o . Angular discriminating filters are therefore possible with these films. The optical response of these materials as a function of applied field is also shown to be dependent on the ratio n p /n o as is the contrast exhibited by information displays. Methods for measuring the scattering cross section of a nematic droplet are also described.
Available at: http://works.bepress.com/john_west/20/