A beam distorsion technique applied to the measurement of nonlinearities in CdSxSe1-x doped glasses

Recently a single beam technique for measuring both the non-linear refractive index and non-linear absorption of transparent materials has been proposed by Sheik-Bahae et al. IEEE J. Quantum Electron., vol.26, p.760, 1990; in which the transmittance of a sample is measured through a finite aperture in the far field as the sample is moved along the propagation path of a focused Gaussian beam. The sign and magnitude of the non-linear refractive index and the value of absorption changes can be deduced from the transmittance curve. In the present paper this technique has been applied to evaluate both the thermal and electronic non-linear changes of refractive index and of absorption of some Schott semiconductor doped glasses by using the CW and pulsed regime.