Research On Random Laser With Coherent Feedback

The random laser is a new laser that has special theorem which people have discovered in recent years. The formation of the random laser is closely correlated with the Anderson limitation. It is a laser that makes light amplifying by the coherent feedback which is provided by the scattering effect make, and that there is light output in many directions, so it has a widely applying prospect. In this article, we have studied the form of scattering of the recurrent light in random laser with coherent feedback, and the competition of mode, and the two kinds of light' s limitation in random laser.In the third part, on the base of predecessor' s experiment data and theory, we expatiate on the phenomenon of the amplifying spontaneously of light, and through analyzing the experiment data, we show that the transition from the amplifying spontaneously radiating to laser radiating is a gradual one. According to the result of the experiment, Cao.H got the conclusion that this transition occurs when the averagely free path of scattering is decreased from 14λ to 5λ. In the forth part, the form of scattering of the recurrent light in random laser with coherent feedback and the competition of mode are studied. Cao H. proposed that the random laser with coherent feedback is generated by recurrent light scattering (closed loop path formed by multiple scattering). Basing on her standpoint, and through the experiment that the random laser is composing by the laser dyeing liquor including ZnO scattering microparticles(the diameter is about 100nm), we propose the simplified models of cube and the only one of six surfaces is mirror for ZnO scattering particle. Utilizing Cao. H' s experiment data, we analyze and calculate the relative probability...