An interesting aspect of this thesis should be mentioned right at the beginning. It was shown that the higher harmonics generated by non-centrosymmetric bonded electrons can take on properties of negative index systems. By controlling the nonlinearity, tailor-made optical metamaterials with a defined negative refractive index are possible. This becomes interesting in the context of the fact that matter waves with a refractive index of exactly minus one form the perfect microscope. A suitable set of new characteristic optical response tensors, which are no longer Lorentzartig in view of the newly gained knowledge, were derived for non-centrosymmetric media and their importance for the various nonlinear orbital response functions was shown and discussed. The nonlinear resonant denominator function can α be rewritten depending on the strength of the nonlinearity, where noncentrosymmetric matter scales in the nonlinear mode with negative SKEWNESS and centrosymmetric matter, as well as the transition bulk / surface with positive SKEWNESS, and the harmonics can be classified depending on the introduced parameters p and q. The nonlinearity in the denominator function takes into account the occurring skewness and the destabilization of increasing nonlinear amplitudes, in contrast to the current literature (e.g. Boyd), in which α occurs only as a proportionality factor, in which the amplitude is linearly and directly influenced and no destabilization of the amplitudes in the nonlinear regime is described. Due to the symmetry of non-centrosymmetric matter, no longitudinal modes are capable of propagation. The nonlinear dielectric spectral response function has singularities for non-dissipative matter at any transition frequency. The analysis taking into account dissipative effects showed an elimination of these singularities. You get curves with negative skewness. In the identified regions of negative dielectric function, a real refractive index of less than 1 exists. The refractive index is imaginary there, which is usually characteristic of surface plasmons. In this area, it is in principle possible to produce optical metamaterials by setting suitable nonlinearity. In the linear case, the spectral function has a zero position, so that longitudinal modes can also propagate for this. Variation of nonlinearity causes a very large positive or negative skew depending on the sign and shows frequency conversion. (Truncated by viXra Admin to < 400 words)