INTENSITY CORRELATIONS AND FLUCTUATIONS OF WAVES TRANSMITTED THROUGH RANDOM MEDIA

摘要

The correlations between waves transmitted through random media are analyzed by use of a random matrix approach. Although the intensity and conductance fluctuations are practically independent of the sample length, the correlations present an unexpected strong dependence on the length of the disordered region. Interestingly, we show that the long range correlations C~((2)) and C~((3)), usually associated with intensity and conductance fluctuations, respectively, become negative as the length of the system decreases. Flux conservation is shown to be the main source of negative correlations in the quasi-ballistic regime.