Zoom systems with tuneable lenses and linear lens movements

Abstract

Background: Classical zoom lenses are based on movements of sub-modules along the optical axis. Generally, a constant image plane position requires at least one nonlinear sub-module movement. This nonlinearity poses a challenge for the mechanical implementation. Tuneable lenses can change their focal length without moving along the optical axis. This offers the possibility of small system lengths. Since the focal range of tuneable lenses with significant aperture diameters is still limited, the use of tuneable optics in zoom lenses is usually restricted to miniaturized applications. Methods: To solve the challenge of the nonlinear movement in classical zoom lenses and the limitations of tuneable lenses for macroscopic applications we propose a combination of both concepts. The resulting 'Hybrid Zoom Lens' involves linear movements of sub modules as well as changing the focal length of a tuneable lens. The movements of the sub-modules and the focal length tuning of the lens are already determined by the collinear layout of the zoom lens. Therefore, we focus on collinear considerations and develop a method that allows a targeted choice of specific collinear layouts for our 'Hybrid zoom lenses'. Results: Based on examples and an experimental setup we demonstrate the feasibility of our approach. We apply the proposed method to examples of classical zoom lenses and zoom lenses based exclusively on tuneable lenses. Thereby we are able to show possible advantages of our 'Hybrid zoom lenses' over these widespread system types. Conclusions: We demonstrate important collinear considerations for the integration of tuneable lenses into a zoom lens. We show that the combination of classical zoom lens concepts with tuneable lenses offers the possibility to reach smaller system lengths for macroscopic zoom lenses while requiring only a small focal tuning range of the tuneable lens.

Design method for zoom systems based on tunable lenses

“…Looking back at Eq. (26) shows that the object to image distance for group 4 depending on F 0 1 can be written as E Q -T A R G E T ; t e m p : i n t r a l i n k -; e 0 3 2 ; 1 1 6 ; 3 5 4…”

“…Unlike other methods for classical zoom lenses, [23][24][25] our method sets the main focus on mapping the first-order solution space applying traditional thin lens aberration equations. 26,27 This is based on an extension of ideas presented in our earlier work. 26 A similar approach for telescopes consisting of two adaptive mirrors was demonstrated in Ref.…”

“…26,27 This is based on an extension of ideas presented in our earlier work. 26 A similar approach for telescopes consisting of two adaptive mirrors was demonstrated in Ref. 28.…”

Optical zoom imaging systems using adaptive liquid lenses

“…A hybrid 3× optical zoom lens consisting of two solid sub-modules and a liquid lens was investigated by Lenk et al As shown in figure 9(a), the second sub-module was an adaptive liquid lens (APL™-1050, Holochip Corp). The adaptive liquid lens can not only be mechanically moved to realize the zooming function as a variator but it can also change its focal length simultaneously to realize the focusing function as a compensator to keep the image plane stationary [100]. Similarly, a 3× zoom system (the focal length range was 4.3 mm to 12.90 mm) consisting of a prism and two lens groups was proposed by Park et al As shown in figure 9(b), the second group was moved to the first group to obtain a long focal length to realize the zooming function.…”

Measurement of step surface contour based on variable sampling phase shift interference phase extraction algorithm based on selective sampling

“…With the rapid development of interferometry technology, phase-shifted interferometry (phaseshifting interferometry, PSI), the primary presentative of interferometry technology, becomes one of the main methods in modern measurement of optics surface shape. From the early phase-shift algorithm including the Hariharan algorithm and the Schwider algorithm to the current frequency-conversion phase-shift algorithm including the iterative algorithm and the principal element analysis method, we can come to a conclusion that the research of the frequency conversion phase shift algorithm has become the trend of modern phase-shift interferometry research [1]. Although the principal element analysis (PCA) and Advanced iterative algorithm (AIA) can be used to recover the phase information from a large number of phase-shifted interferogram efficiently [2][3][4][5], a series of error sources and the complexity of measured surface do exist in the actual measuring process [6,7].…”