<p>The refractive index (RI) of anisotropic ferroelectric optical waveguide materials changes depending on which way the light wave is moving. Being a negative uniaxial crystal, Lithium Niobate (LiNbO₃/LN) has an oblate ellipsoid of revolution optical indicatrix (in the XZ plane) with its optic axis orientated along the Z-axis, and a unique circle of revolution optical indicatrix (in the XY plane) is observed with its optic axis along the Z-axis. Also, the refractive indices for the above-said orientations are observed using point dipole approximation (PDA) in XZ and XY planes and are well-suited with the locus of LiNbO₃ optical indicatrix values. The variation of refractive index (ordinary <i>n</i>o and extraordinary <i>n</i>e refractive index) from ordinary RI, <i>n</i>_<i>o</i> = 2.28674 (maximum) to extraordinary RI, <i>n</i>_<i>e</i> = 2.2024 (minimum) is observed at an interval of 10° by considering the optic axis along the Z-axis, and an oblate ellipsoid is observed in the XZ plane. There is no variation of refractive index <i>n</i>_<i>o</i> = 2.28674, observed at an interval of 10° and a circular indicatrix in the XY plane is observed. In PDA, one must set the possible polarisability values of constituent ions of LiNbO_3. From the wavelength dispersion data, the variation of polarisability values of constituent ions of LiNbO₃ is also studied using PDA.</p>