Based on a unified approach in the ray approximation, the focusing properties of Fresnel lenses and kinoform lenses are considered and compared. Particular attention is paid to the energy efficiency, chromatic focal shift and resolving power of these elements. It is shown that the Fresnel lens with same-depth segments is an analogue of the harmonic kinoform lens operating in high diffraction orders. A mechanism of the formation of the diffraction pattern in the focal plane of a Fresnel lens with equidistant annular segments is analyzed. It is shown to differ from the corresponding diffraction pattern formed by a conventional refractive lens by a smaller amount of energy coming to the main maximum and a significant proportion of energy transferred to the side maxima. The target audience of this article is students and graduate students, as well as specialists in the fields of science and technology where optical methods and instruments play an ever increasing role.
Comparative analysis of the Fresnel lens and the kinoform lens
