Reduction in generalized conductance with increasing gain in amplifying Anderson-localized systems.

The consequences of a nonconservative environment on the transport of photons under conditions of Anderson localization in a disordered system are a topic of great interest. In this work, we experimentally demonstrate the systematic decrease in the localization length of a quasi-one-dimensional localizing system when gain is added to it. We quantify the generalized conductance of the system using the variance of the fluctuations in the localized eigenfunctions and show a decrease in conductance with gain. We theoretically model this system using a combination of transfer matrix calculations and rate equations for a two-level lasing system and find very good qualitative agreement with the experimental results. We show that the generalized conductance in higher disorder can be emulated in weak disorder using the appropriate gain. The decreasing conductance is explained using the reduced probability of outcoupling of photons relative to their peak position within the system.