Numerical Simulation On Random Lasing Emission Properties And Experimental Study On Neodymium Glass Powder

The optical cavity is the essential part of the conventional laser, which determines the mode and direction of the output light. And the scattering is not conducive to the formation of the laser, which should be avoided. While in random lasers, light is confined by multiple scattering which determines the laser’s properties of the emission, including the model, threshold value, direction of laser, and so on. Random lasing has interesting physical properties and importance in technological applications, so it is studied widely. In this master’s thesis, I do some work about the random lasers’theoretical problem and carry out some experiment.The contents of the thesis include:(1) We simulated numerically that the one-dimensional random gain medium pump by double-pulse and get the following conclusions:the pumping process has an accumulate effect for the fixed sample which pumped by a high rate pump.(2) We establish a new physical model to reveal the cross relaxation in the random laser. We found that we can get532nm light when pumped by the381nm light through cross relaxation and design the experiment program for the later experiment.(3) We design and construction the optical experimental path to measure photon transport mean free path of our samples by the coherent backscatter method. The light intensity is so weak from the sample that we design the photoelectric detection circuit. We analysis the result why we did not achieve the desired and propose some solutions.(4) Making neodymium glass powder sample and learning DG535detect the radiated light form the neodymium glass sample which pumped by the femtosecond laser.