<p>Vat photopolymerization has gained significant attention in the production of optical components owing to its freeform characteristics and exceptional customizability. In this context, birefringence and optical homogeneity of the 3D printed component are key parameters towards its performance. Although the optical properties of polymers are well understood, there is limited literature regarding the optical properties of 3D printed parts, especially in hybrid sol-gel materials. This study investigated the optical homogeneity and birefringence of an aluminum-phosphate-silicate sol-gel hybrid material fabricated via laser scan vat-photopolymerization. The materials exhibited striae and birefringence, which were analyzed by polarized and unpolarized micro-Raman scattering spectroscopy, quantitative phase imaging, and polarimetry to assess molecular alignment, polymerization degree, refractive index, and to identify birefringence, respectively. Our results indicated that the optical properties of the 3D printed hybrid materials are explained by the same mechanisms as those of polymeric materials. The irradiance profile produced by a single laser scan creates a polymerization degree profile from the center to the borders of the beam path, resulting in a refractive index variation of 1.3 × 10^–4. When layers are printed and immediately superimposed, this modulation accumulates, resulting in striae perceptible to the naked eye. Finally, birefringence is generated via a stress-freezing mechanism during the localized photopolymerization.</p> Graphical Abstract <p></p>