Polymer fiber mats provide white and full-color tunable lasing

Random Lasing has become highly advantageous for achieving white laser emission. Utilizing multiple light scattering in disordered media allows for cost-effective and flexible designs, as well as the seamless integration of multiple multicolor gain materials. However, generating light that closely meets the D65 illumination standard remains challenging due to energy transfer between chromophores. To address this issue, effective spatial separation of gain media is required. Here, we present a solution to the problem using hierarchically designed polymer fiber mats with spatially distributed red, green, and blue (RGB) laser dyes to achieve controlled and tunable multicolor and white lasing. While electrospun fibers are well-studied, their use for multicolor random lasing is demonstrated here for the first time. Our results demonstrate outstanding spectral tunability, aligning well with industrial color standards such as sRGB, Adobe RGB, and DCI-P3. The white lasing closely matches D-series white illuminants, including D65, D55, and D75 standards, with coordinate deviations as low as approximately 0.2 to 3%, surpassing previously reported values for organic, hybrid, and inorganic systems. By limiting energy transfer, our approach enables precise lasing control, demonstrating that fiber mats are versatile for next-generation random lasing applications. These findings advance technologies in Li-Fi, laser displays, optical sensors, switches, and modulators, bringing tunable lasers closer to commercialization.