Non-linear self-action effect and absolute two-photon absorption coefficient in CdS

The role of non-linear self-action (SA) effect on absolute two-photon absorption (TPA) coefficient measurements has been quantitatively evaluated in CdS. The SA-effect and the absolute TPA coefficient have been measured by “external SA” and “one-channel” method respectively, using a single mode ruby laser. When the SA-effect has been taken into account, a sensible variation in TPA coefficient evaluation has been found.