9B2 - The nature of the laser transition in CdS crystal at 90°K with two-photon excitation

An oscillation at the wavelength 4946 A in cadmium sulfide crystal is produced by two-photon excitation by ruby laser radiation. A two-photon absorption coefficient is measured at the wavelength 6943 A. The two-photon absorption coefficient is proportional to the light beam intensity and is equal to 1.0 cm
^-1
at 50 W/cm
²
. The excitation lifetime in excited state is 10
^-9
to 10
^-11
seconds. It is proved that the oscillation in cadmium sulfide is due to the coupled excitations.