Fiber-coupled random laser

We demonstrate that in fiber-coupled random laser, the threshold energy is twofold reduced and the slope efficiency is fivefold increased when the tip of the fiber is relocated from the surface to the depth of the powder volume. High absorption efficiency, 85%, and high conversion efficiency of population inversion to stimulated emission, 90%, make fiber-coupled random laser a promising laser source. The demonstrated 5% quantum slope efficiency of the "ready to use" random laser emission delivered by the fiber can probably be significantly increased after the optimization of the coupling of emission to the fiber. (c) 2005 American Institute of Physics.