The Anisotropic Refractive Indices of Aligned MBBA Liquid Crystal Films

The anisotropic refractive indices of unidirectionally and horizontally aligned MBBA liquid crystal films were determined by means of polarimetry and transmission measurements in the wave length region 0.42 to 0.70μ at room temperature. The analyses show that absorption in this wave length region is negligibly small (k‖ ≅ k 1 ≅ 0.0005) and that n || decreases while n 1 increases with increasing wave length with the net result that the birefringence Δn(=n||- n⊥) decreases rapidly first from 1.06 at λ = 0.42 μ then slowly to 0.28 at λ = 0.70μ.