LOCALIZATION OF LIGHT - DUAL SYMMETRY BETWEEN ABSORPTION AND AMPLIFICATION

We study the propagation of radiation through a disordered waveguide w ith a complex dielectric constant epsilon, and show that dual systems, which differ only in the sign of the imaginary part of epsilon, have the same localization length. Paradoxically, absorption and stimulated emission of radiation suppress the transmittance of the waveguide in the same way.