Direct Creation of Excitonic Molecules in CuCl by Giant Two-Photon Absorption

Abstract

The two-photon absorption spectrum due to excitonic molecules is measured in CuCl at 77 and 4.2°K. We measured values of the two-photon transition cross section of the order of ${10}^{-44\mathrm{}}$ ${\mathrm{cm}}^4$ sec and estimated a peak value of ${10}^{-42\mathrm{}}$. The binding energy of the molecule is found to be 255 ${\mathrm{cm}}^{-1\mathrm{}}$.