Improvement of the random laser efficiency

The article is devoted to the problem of random laser parameters optimisation. The investigated random laser was made of R6G solid solution in polymer with embedded scattering particles. We optimised efficiency of the positive feedback formed in different ways: by multiple scattering within sample volume and by the sample surface reflection. The total feedback of the random laser can be varied by the medium thickness change. We also demonstrated that the raising of the medium surface reflectivity can cause extra increasing of the efficiency of the positive feedback. According to the conclusions we proposed methods of the random laser efficiency improvement. These methods allow up to 6 times increasing of the random laser efficiency.