Patent ID: 9046735
Filing Date: 2015-06-02
Classification: G01N,G02F

Abstract:
1. A method for determining second-order nonlinear optical coefficients of a non-centrosymmetrical material, comprising: providing a specimen made at least in part of said material, causing a first optical signal and a second optical signal having a first pulsation and a second pulsation and a first polarization state and a second polarization state, respectively, to impinge upon said specimen in such a way that said specimen generates a sum optical signal having a third pulsation and a third polarization state, said third pulsation being equal to the sum of said first and second pulsations, said third polarization state being a function of said first and second polarization states, wherein causing the first optical signal and the second optical signal to impinge upon said specimen includes causing impingement of said first and second optical signals with linear polarizations in such a way that said sum optical signal is linearly polarized, said first and second polarization states being defined, respectively, by a first polarization angle and a second polarization angle; determining a plurality of measurements of power associated to said sum optical signal, and determining said second-order nonlinear optical coefficients on the basis of said plurality of measurements of power; wherein the step of determining the plurality of measurements of power includes performing measurements of power of said sum optical signal as said first and second polarization states vary, and includes the step of varying said first and second polarization angles by means of polarizing means controllable to vary said first and second polarization angles in such a way that they assume a plurality of pairs of respective values, said values being comprised in a range with a width of at least 180°.