New measurements of the two-photon absorption in GaP, CdS, and ZnSe relative to Raman cross sections

Abstract

The two-photon absorption (TPA) coefficient in GaP, CdS, and ZnSe was measured at 3.56 eV using the TPA normalization technique and at 3.18 eV using a new calibration method. In this method the TPA effect is normalized by comparing the two-photon nonlinear attenuation with stimulated Raman gain in materials with known Raman cross section. By utilizing different Raman modes, reliable TPA cross sections, independent of the laser characteristics, are obtainable. When combined with recently published cross sections at 3.91 eV the TPA results at 3.18 and 3.56 eV show interesting spectroscopic features.