Controlling the random lasing action from GaAs/AlGaAs axial heterostructure nanowire arrays.

Controlling the random lasing action from disordered media is important to obtain customizable lasers with unprecedented properties. In this paper, systematic investigations of random scattering based on GaAs/AlGaAs axial heterostructure nanowire (NW) arrays are presented. By manipulating the diameter and density of GaAs/AlGaAs axial heterostructure NWs during growth, different types of random lasers (Anderson localized and delocalized random lasers) have been successfully realized. The threshold, Q factor, and spatial coherence of these two types of lasers are experimentally discussed and analyzed. Finally, a proof-of-concept demonstration of speckle-free imaging based on the NW lasers has been conducted. This research enables the tunability of random lasers with exceptional performance and lays the foundation for achieving random lasing control.