Unlike OLED materials, which necessitate close orbital contact and molecular coupling for efficient charge transport, emission-focused applications such as solar concentrators, light harvesting systems, and imaging labels do not require charge conduction. In these cases, electronic decoupling is highly desirable. This precisely applies to the developed PDI-based fluorescent polymers. As a proof of concept, preliminary applications of the optimized PDI polymers were assessed for potential use in fluorescent 3D waveguides and white phosphor-converted LEDs. We first 3D printed Y-shape waveguides by digital light processing using a commercial transparent resin. Two different branch angles-30º and 60º were selected to evaluate the waveguiding efficiency. The printed objects were coated with PDI-tetraPS (DP100) on the surface through dip coating, and significant waveguiding effect was observed upon laser irradiation at 532 nm at the straight edge, due to the total internal reflection. Their performance was characterized by measuring the transmittance at the edge of the two branches. This was conducted by recording the laser emission transmission directly from the straight edge of a waveguide, while waveguide emission was collected from the angular edge of the waveguide. As shown in Figure , A to C, the waveguide with branch angle of 30º showed a much higher transmittance compared to the one with branch angle of 60º (0.25 vs. 0.15), which is consistent with the result in literature. This simple strategy may enable versatile fabrication of fluorescent 3D waveguide from different type of materials for various potential applications.