Sirii Y.A.

Method for Assessing Modulation Transfer Function of Trifocal Intraocular Lens

The article investigates the quality of images formed by multifocal optical elements. The method for calculating of multifocal diffractive lens modulation transfer function (MTF) at presence of background is proposed. The method is based on a geometric calculation of the intensity of background images and the diffraction efficiency of the main image in each focal plane is considerated. The article has studied the contrast of main images formed by trifocal intraocular lens (IOL).

Infrared Hybrid Lenses with Corrected Spherical Aberration

This paper proposes the method of monochromatic lens spherical aberration correction by designing it as a hybrid lens. This method is based on the equation, which allows obtaining designing wavelength and focal distant of the hybrid lens diffractive part. The spherical aberration of the obtained diffractive part is equal to the refractive part of spherical aberration but has an opposite sign within a given clear aperture. Using this method, we calculate the plano-convex germanium hybrid lens with low f-number, which forms perfect spherical wavefront for the operating wavelength.

Investigation of Kinoform Element Chromatism

The paper investigates the chromatic characteristic of the kinoform element in a given spectral range. Based on the well-known chromatism theory we obtain more exact expressions of the chromatic focus shift and the dispersion coefficient. The enhanced chromatism theory determined that the chromatic focus shift and the dispersion coefficient depend not only on a spectral range but also on a Fresnel zone number. Based on the enahnced theory we analyze the kinoform chromatism in the spectral range of 8–12 µm.

Monochromatic Aberration of Kinoform Element

Based on the aberration model of thin lens, we obtain the monochromatic aberrations of the paraxial kinoform element with a high efficiency in the first diffraction order. We consider the dependence of field aberrations from the aperture position. Moreover, we determine the conditions, under which the kinoform element is free from some aberrations. We also study the conditions of the variation range of each field aberration minimum in the spectral range of 8–12 microns for the element with specific design parameters.