Evaluating the influence of the refractive index dispersion of a harmonic lens on focusing properties

We performed theoretical and numerical analysis of the focusing properties of a harmonic diffractive lens taking into account the dispersion of the refractive index. It was shown that the harmonic lens is characterized not only by the appearance of additional local foci, but also by a shift of the main foci even for multiple wavelengths, which is associated with the chromatic dispersion of the lens material.