K₃₃/K₁₁ determination in nematic liquid crystals: An optical birefringence technique

Optical birefringence patterns of nematic liquid crystals constrained to supramicrometer capillary tubes with homeotropic anchoring are sensitive to the detailed bulk elastic properties of the nematic material. The bend‐to‐splay elastic constant ratio (K₃₃/K₁₁) is estimated by comparing the escaped‐radial nematic director field observed via optical polarizing microscopy to simulated textures predicted by the Frank elastic theory.