  Absorption induced transparency is an optical phenomenon that occurs in
metallic arrays of nanoholes when materials featuring narrow lines in their
absorption spectra are deposited on top of it. First reported in the visible
range, using dye lasers as cover materials, it has been described as
transmission peaks unexpectedly close to the absorption energies of the dye
laser. In this work, amplification of light is demonstrated in the active
regime of absorption induced transparency. Amplification of stimulated emission
can be achieved when the dye laser behaves as a gain material. Intense
illumination can modify the dielectric constant of the gain material, which in
turn, changes the propagation properties of the plasmonic modes excited in the
hole arrays, providing both less damping to light and further feedback,
enhancing the stimulated emission process.
