<p>This paper investigates the use of the laser powder bed fusion (LPBF) process to fabricate optically non-uniform quartz glass. A novel grooved substrate was proposed, which facilitates the bonding strength between the printed specimen and the substrate compared to a flat substrate. During laser exposure, the grooved substrate enhances the mixing of the substrate and glass materials, forming a transition layer. This transition layer not only improves the bonding between the glass specimens and the metal substrate but also increases visible light absorption of the bottom surface. The study also analyzed the formation process of internal pores within the printed specimens. Compared with the hatch distance, the laser power has a greater impact on the forming quality. Compared with the surface absorption mode of the CO₂ laser, the YAG laser used in this study exhibits a volumetric absorption mode. As the printing height increases, the laser energy penetrates the surface layer of the sample, resulting in insufficient melting of the surface powder. Therefore, a height-adaptive optimization strategy was proposed to mitigate the negative effects of the volumetric absorption model of quartz glass. This strategy successfully fabricates the quartz glass specimens with a porous structure, where the pore structure induced optical phenomena such as transmission and scattering on the top surface, leading to distinct optical non-uniformity between the top and bottom surfaces of the quartz glass.</p>