Normalization technique for accurate measurements of two-photon absorption coefficients

Abstract

A new technique for accurate measurement of the two‐photon absorption (TPA) coefficient relative to the known TPA coefficient of a reference material is presented. It is shown that the ratio between the transmitted energies of two identical laser pulses through the unknown and the reference materials is a constant which is independent of the laser intensity if a filter of an appropriate transmission value F is put in front of the reference material. The ratio between the two TPA coefficients is simply related to F. Using the outlined technique the ratios between the TPA coefficients of three semiconductor samples were measured with an accuracy of ±10%