  Electron-glasses can be readily driven far from equilibrium by a variety of
means. Several mechanisms to excite the system and their relative merits are
reviewed. In this study we focus on the process of exciting electron-glasses by
interaction with near infrared radiation. The efficiency of this protocol
varies considerably among different electron-glasses, but it only weakly
depends on their resistance at liquid helium temperatures. A dramatic
enhancement of the excitation efficiency is observed upon doping crystalline
indium-oxide with Au. Some enhancement is observed also in samples doped with
Pb but this enhancement fades away with time unlike the situation in the
Au-doped samples. Several structural and analytical tools are used to
characterize the changes in the materials that may be responsible for these
effects. Possible routes by which high-frequency electromagnetic fields take
the system far from equilibrium are discussed.
