We investigated deformation of InP that was introduced by thin, narrow, dielectric SiNx stripes on the (100) surface of InP substrates. Quantitative optical measurements were performed using two different techniques based on luminescence from the InP: first, by degree of polarization of photoluminescence; and second, by cathodoluminescence spectroscopy. The two techniques provide complementary information on deformation of the InP and thus together provide a means to evaluate approaches to simulation of the deformation owing to dielectric stripes. Ultimately, these deformations can be used to estimate changes in refractive index and gain that are a result of the stripes.