Thin films of hexagonal boron nitride (h-BN) have been prepared using a reactive ion plating process. Investigations of guiding and optical properties of films have been performed using m-line spectroscopy. Both ordinary and extraordinary refractive indices are, respectively, determined from TE and TM mode excitation. Furthermore, refractive index profile analysis using an improved inverse WKB method reveals a gradient-like behavior indicating an optical inhomogeneity of the deposited films along the thickness. An optical anisotropy study confirms the films uniaxial nature with a birefringence, Δn, of about 0.11.