Influence of the linear inhomogeneity of a medium on the second-harmonic generation under nonlinear conditions

An analysis is made of the influence of the linear inhomogeneity of the refractive index on the second-harmonic generation under nonlinear frequency conversion conditions. The results of numerical calculations of the phase-matching curves are given for different lengths of a longitudinally inhdmogeneous nonlinear medium and plane-wave fundamental-frequency radiation. An investigation is made of the distribution of the density of the second harmonic at the exit from a linearly inhomogeneous crystal. A description is given of the apparatus used in an investigation of the influence of a longitudinal linear inhomogeneity on the second-harmonic generation. The results of this investigation are reported.