<p>Laser-based powder bed fusion of polymers (PBF-LB/P) is one of the most promising next-generation manufacturing technologies because of its high design flexibility and support-free manufacturing capability. However, its productivity remains lower than that of conventional methods, and reducing the build time is a key challenge. This study aimed to accelerate the build process by reducing the number of layers through increasing the layer thickness and investigated the effects of powder bed optical properties on this approach. Accordingly, a highly transmissive powder bed was developed using a near-infrared laser and an optical absorber, which was compared with a conventional low-transmissive powder bed fusion process using a CO₂ laser. The heating behavior, melting state, and interlayer adhesion were evaluated for each layer thickness. Furthermore, transient heat-transfer simulations were conducted to quantify the influence of powder bed transmissivity on the thermal distribution during processing. The results indicate that, in a near-infrared laser-based fusion process, the powder bed maintains its mechanical properties up to a layer thickness of 200&#xa0;μm, with deeper heating contributing to improved interlayer adhesion. These findings support the feasibility of increasing the layer thickness to enhance the productivity of PBF-LB/P without compromising part quality by appropriately designing the optical properties of the powder bed.</p>