Red–green–blue random lasers for high-resolution speckle-free color imaging in scattering environments

Random lasers (RLs) combine laser-like brightness with low spatial coherence, making them an attractive illumination source for speckle-free imaging and full-color displays. In this study, we developed a high-resolution, speckle-free color imaging system illuminated by red, green, and blue RLs based on DCM, Fluorescein 548, and Coumarin 440 doped PVA/DMSO media containing SiO2 nanoparticles. The red–green–blue RLs exhibit emission wavelengths centered at approximately 659, 555, and 437 nm, with lasing thresholds of 64.3, 76.2, and 112.6 μJ/pulse, respectively. Under scattering environments, due to the low spatial coherence of RLs, the resolution of images illuminated by the red, green, and blue RLs reaches approximately 456, 512, and 575 lines/mm, respectively. In a turbid water environment, the microscopic images of bee wings illuminated by the red–green–blue RLs remained clear. Additionally, we demonstrated that the red–green–blue RLs can be used for programmable high-resolution color displays. This study not only proposes a color imaging strategy using red–green–blue RLs, but also demonstrates the potential of the RLs in high-resolution microscopic imaging, speckle-free imaging, biological imaging, and programmable color displays.