Advantages of random lasers in high-resolution speckle-free bio-imaging.

Random lasers, which bridge the gap between the conventional light-emitting diodes (LEDs) and coherent laser diodes (LDs), have been proven as promising light sources to suppress speckle patterns in optical imaging. In this study, to explore the potential of random lasers for speckle pattern suppression within bio-imaging, we designed a random laser based on a gold (Au)/graphene hybrid structure, with its emission guided by an optical fiber into the microscope system. The suppression performance of the speckle patterns in scattering environments has been systematically investigated. Our experimental results show that the sharpness factors of the images can be improved significantly, and therefore, higher-resolution images with suppressed speckle patterns can be obtained in scattering environments with the help of the proposed random laser. Moreover, we demonstrated that compared to conventional lasers, random lasers have significant advantages in obtaining high-resolution speckle-free bio-imaging. This study confirms the significant potential of random lasers in bio-imaging, minimally invasive medicine, and damage detection.