Raman-Nath nonlinear diffraction in second harmonic generation

The observation of multiple-order Raman-Nath nonlinear diffraction of beam by a one-dimensional nonlinear chi
⁽²⁾
grating is reported . The observed second harmonic (SH) diffraction patterns in a one dimensional grating is seen in a LiNbO
₃
crystal. The observed effect can find application as non-distractive testing of the poling structure and in second harmonic nonlinear microscopy.