Vortex random lasing with tunable wavelength and orbital angular momentum

Random lasing with special structured light field has broad application prospects in various fields. However, the complex spatial modes of random lasing increase the difficulty of light field regulation and limit its practical application. Here, a vortex random lasing with dynamically tunable wavelength and orbital angular momentum is proposed based on the microfluidic channel. Different color random lasers are integrated into the same microfluidic channel for coarse control of the emission wavelengths from 462 to 685 nm by dynamically controlling the liquid flow. A special-shape cavity with a variable size of a gain region is further constructed to finely manipulate the emission wavelengths. Moreover, the vortex random lasing with tunable orbital angular momentum mode from -50 to 50 is realized. The results provide an outstanding strategy for generating the partially coherent vortex beams and may promote the practical applications of random lasers in the fields of sensing, imaging, and communication.