TRANSMISSION AND REFLECTION FROM A DISORDERED LASING MEDIUM

A numerical study of the statistics of the transmission (t) and reflec tion (r) of quasiparticles from a one-dimensional disordered lasing or amplifying medium is presented. The amplification is introduced via a uniform imaginary part in the site energies in the disordered segment of the single-band tight-binding model. It is shown that t is a non-s elf-averaging quantity. The crossover length scale above which the amp lification suppresses the transmittance is studied as a function of am plification strength. A new crossover length scale is introduced in th e regime of strong disorder and weak amplification. The stationary dis tribution of the backscattered reflection coefficient is shown to diff er qualitatively from the earlier analytical results obtained within t he random-phase approximation.