Absorption effect in the calculation of a second-order nonlinear coefficient from the data of a Maker fringe experiment

The effect of light absorption by sample in the analysis of Maker fringe data for estimating a second-order nonlinear coefficient has been studied experimentally. Two theories, one by Jerphagnon and Kurtz that neglects the absorption effect and one by Herman and Hayden that takes into account the absorption effect, were compared with the experimental results. It was found that Jerphagnon and Kurtz's formula was unable to predict correctly not only the magnitude but also the incident angle dependence or the sample thickness dependence of the second harmonic signal generated by the sample with strong absorption, whereas the theory by Herman and Hayden was able to make those predictions fairly well. It was also found that the error in the estimated nonlinear coefficient when one uses Jerphagnon and Kurtz's formula could be as large as 2-4 times the true value, depending on sample thickness. (C) 1998 Optical Society of America.