1.7 Nonlinear optical properties

This chapter deals mainly with harmonic generation and parametric interactions in anisotropic crystals. Section 1.7.2 describes second- and higher-order electric susceptibilities. Section 1.7.3 is devoted to propagation phenomena, particularly in the case of three-wave and four-wave interactions, to the conditions of phase matching and to resonant and non-resonant second harmonic generation. Section 1.7.4 shows how the basic nonlinear parameters are determined and Section 1.7.5 gives a survey of the main nonlinear crystals. Keywords: ABDP and Kleinmann symmetries; Gaussian beams; Maker fringes; Manley–Rowe relations; Sellmeier equations; acceptance bandwidths; biaxial classes; biaxial crystals; coherence length; contraction; conversion efficiency; dielectric polarization; dielectric susceptibility; dielectric tensor; difference-frequency generation; electric polarization; field tensors; figure of merit; index surface; nonlinear crystals; nonlinear optics; optical parametric oscillation; parametric amplification; phase matching; phase mismatch; polarization; quasi phase matching; second harmonic generation; sum-frequency generation; third harmonic generation; undepleted pump approximation; uniaxial classes; uniaxial crystals; walk-off