Antonin Miks

Method of zoom lens design

Optical systems with variable optical characteristics (zoom lenses) find broader applications in practice nowadays and methods for their design are constantly developed and improved. We describe a relatively simple method of the design of zoom lenses using the third-order aberration theory. It presents one of the possible approaches of obtaining the Seidel aberration coefficients of individual members of a zoom lens. The advantage of this method is that Seidel aberration coefficients of individual elements of a given optical system can be obtained simply by solving of a set of linear equations. By using these coefficients, one can determine residual aberrations of the optical system without detailed knowledge about the structure of its individual elements. Furthermore, we can determine construction parameters of the optical system, i.e., radii of curvature and thicknesses of individual elements of a given optical system. The proposed method makes it possible to determine which elements of the optical system can be designed as simple lenses and which elements must have a more complicated design, e.g., doublets or triplets.

Analysis of two-element zoom systems based on variable power lenses

Traditional optical systems with variable optical characteristics are composed of several optical elements that can be shifted with respect to each other mechanically. A motorized change of position of individual elements (or group of elements) then makes possible to achieve desired optical properties of such zoom lens systems. A disadvantage of such systems is the fact that individual elements of these optical systems have to move very precisely, which results in high requirements on mechanical construction of such optical systems. Our work is focused on a paraxial and third order aberration analysis of possible optical designs of two-element zoom lens systems based on variable power lenses with a variable focal length. First order chromatic aberrations of the variable power lenses are also described. Computer simulation examples are presented to show that such zoom lens systems without motorized movements of lenses appear to be promising for the next-generation of zoom lens design.

Generalized refractive tunable-focus lens and its imaging characteristics

Conventional lenses made from optical glass or plastics have fixed properties (e.g. focal length) that depend on the index of refraction and geometrical parameters of the lens. We present an approach to the problem of calculation of basic paraxial parameters and the third order aberration coefficients of compound optical elements analogical to classical lenses which are based on refractive tunable-focus lenses. A detailed theoretical analysis is performed for a simple tunable-focus lens, a generalized tunable-focus lens, a generalized tunable-focus lens with minimum spherical aberration, and three-element tunable-focus lens (a tunable-focus doublet).

Modification of the formulas for third-order aberration coefficients

New parameters for calculation of third-order aberration coefficients (Seidel aberration coefficients) are introduced. The formulas for Seidel aberration coefficients are linear in these new variables. With these new variables it is possible to calculate the shape and the refractive index of the glass of the individual lenses of the optical system, which was not possible before.

Third-order aberrations of the thin refractive tunable-focus lens

We present an approach to the problem of the calculation of basic paraxial parameters and the third-order aberration coefficients of thin refractive tunable-focus lenses. It is shown that aberration coefficients of the third order of the thin refractive tunable-focus lens can be completely characterized by three functions that depend only on refractive indices of fluids forming the tunable-focus lens and do not depend on the position and size of the object and the position of the entrance pupil.

Analysis of method for measuring thickness of plane-parallel plates and lenses using chromatic confocal sensor

Noncontact optical metrology based on the chromatic confocal principle is becoming increasingly important for fast and accurate measurements of surface topography, distance, and layer thickness in engineering and industry. These sensors are based on the wavelength dependence of longitudinal chromatic aberration of optical systems, and the distance or thickness of the measured sample is coded into spectral information. We provide a theoretical analysis of a problem of the thickness measurement of transparent samples (glass plane-parallel plates or lenses) with respect to material dispersion. Our work deals with a description and analysis of induced measurement errors in the cases of measurement of the thickness of a plane-parallel plate and the central thickness of a lens. Relations are derived for a quantitative evaluation of these errors and a method is presented for minimizing the influence of these errors on the accuracy of measurement.

Three-component double conjugate zoom lens system from tunable focus lenses.

A method for calculation of paraxial parameters of the double conjugate zoom lens is described. Such an optical system satisfies the requirement that the object, image, and pupil planes are fixed during the change of magnification. Formulas are derived for the calculation of parameters of a three-component double conjugate zoom lens system with tunable focus lenses, which enable us to calculate the optical power of individual optical components with respect to the transverse magnification. The main advantage of such an optical system is the possibility to achieve required zooming properties without any mechanical movement of individual components of the zoom lens.

Analysis of three-element zoom lens based on refractive variable-focus lenses

Traditional optical systems with variable optical characteristics are composed of several optical elements that can be shifted with respect to each other mechanically. A motorized change of position of individual elements (or group of elements) then makes possible to achieve desired optical properties of such zoom lens systems. A disadvantage of such systems is the fact that individual elements of these optical systems have to move very precisely, which results in high requirements on mechanical construction of such optical systems. Our work is focused on a paraxial and aberration analysis of possible optical designs of three-element zoom lens systems based on variable-focus (tunable-focus) lenses with a variable focal length. First order chromatic aberrations of the variable-focus lenses are also described. Computer simulation examples are presented to show that such zoom lens systems without motorized movements of lenses appear to be promising for the next-generation of zoom lens design.

Design of a double-sided telecentric zoom lens

A method is presented for the calculation of paraxial design parameters of a double-sided telecentric zoom lens with easy variation of the magnification range. The telecentric lens consists of a zoom lens with a fixed distance between focal points and a lens with a fixed focal length. The third-order aberration analysis is also performed, and spot diagrams are calculated for two f-number values.

Determination of unit normal vectors of aspherical surfaces given unit directional vectors of incoming and outgoing rays: comment

In a recent paper by Lin and Tsai [J. Opt. Soc. Am. A 29, 174 (2012)] there is presented a rather complicated method for derivation of the unit normal vectors of an aspherical surface given the knowledge of the unit directional vectors of the incoming and outgoing rays. In our comment we present a much simpler method that leads to compact equations suitable for practical implementation.