On chip random lasing performance of the acceptor dye in a specially designed linear and zig zag array of microdroplets with intrinsic disorder.

We demonstrate high-quality on chip random lasing of the acceptor dye using a specially designed dynamic linear array of microdroplets with unconventional shapes that do not support the whispering gallery modes. The intrinsic disorder in the droplet array consequent to its dynamic nature is utilized in achieving the randomness in the lasing emission without deliberately adding the disorder as in ordinary random laser systems. The novelty of the generated structure is illustrated by comparing its emission characteristics with two other arrays made of microspheres and microtriangular droplets arranged in a zig zag fashion. We show that only the linear array of microdroplets supports lasing in the acceptor emission. The design of the array structure allows to further reduce the lasing threshold drastically either by incorporating the radiative energy transfer or by tuning the number of acceptor dye molecules. The highly directional, well-controlled, and intense emission of weakly emitting dye generated on chip without the aid of conventional methods opens up a new scheme of random lasing generation mediated by microdroplets.