The Directional Effect on Lasing of Random Medium

When the quasi-periodic quasi-structure of random medium interacts with matching pump light,the interference effect under its whole multiple scattering leads to lasing in random medium.As a result the localized modes of the random laser is correlative not only with pumping frequency and pumped area,but also with the incident direction of pump light.In this paper,take the random laser in ZnO powder for example,the directional effect of the localized mode spectrum is simulated by means of transferring matrix method.