Fiber-assisted cascade-excited colorful random lasing with ring-shaped angular spectrum for imaging

Colorful random lasing with low spatial coherence has significant applications in high-quality imaging and displaying. Here, a dual-channel colorful random lasing with ring-shape angular spectrum (AS) is achieved by using optical fiber (OF) assisted cascade excitation configuration through coupling the donor and acceptor microcavities on an OF. The waveguiding role of OF significantly improves the photon transfer efficiency between the donor and acceptor random lasers (RLs). When the donor RLs are pumped, colorful lasing of green–red, blue-red, and blue-green are obtained at the two endfaces, respectively. By switching the pumping strategies of the coupled RL system with red, green, and blue RLs on the fiber, red, green, blue, and white random lasing is observed from the same endface, indicating the color-programmable characteristics. The obtained random lasing is used as the illumination source to obtain the speckle-suppression colorful images. The results offer a flexible approach for implementing ring-shape AS RLs with significant applications in imaging and display.