Self-induced optical parametric amplification of random laser emission

In the present letter, random laser (RL) emission at 1063 nm was generated by exciting powder NdAl3(BO3)4 nanoparticles at 580 nm in resonance with the Nd3+ transition 4I9/2 → 2G7/2. Thereupon, optical parametric amplification of the RL, due to the nonlinear interaction between the excitation beam and the RL ones with the NdAl3(BO3)4 nanoparticles, was inferred by a deviation of the expected linear input-output intensity behavior. The experimental results are corroborated by numerical simulations. This is the first time that parametric amplification of RL emission, which can trigger fundamental and applied studies, has been demonstrated.