Experimental and Theoretical Investigation of the Polymer Optical Fiber Random Laser with Resonant Feedback

1D random fiber laser is a novel fiber-based laser, which exhibits many unique optical properties and shows great promise for various applications including speckle-free imaging. A multimode and coherent polymer optical fiber random laser (POFRL) is successfully fabricated by doping TiO ₂ nanoparticles and Rh640 perchlorate dyes in the core of a polymer optical fiber (POF). The waveguide effect provided by the POF greatly increases the multiscattering events for light propagation and results in laser cavity with much shorter length than the scattering mean free path. As an illustration of potential applications, a clear speckle-free imaging is demonstrated using the POFRL as the illumination source. Furthermore, a four-level Monte Carlo method-based numerical model is proposed to describe the lasing dynamics in POFRL. The model supports the experimental work in the research field of POFRL.