A 7.5X Afocal Zoom Lens Design and Kernel Aberration Correction Using Reversed Ray Tracing Methods

Abstract

This thesis presents a design of an afocal 7.5X zoom lens with maximum resolution of 0.68μm followed by a reversed ray trace method to show and correct kernel aberrations in zoom lens, with some examples. In Chapter 1, some fundamentals of geometric optics are introduced to help understanding lens design, including terminology, aberration theory, and methods to quantify a lens system performance. Chapter 2 starts with a brief introduction on zoom lens system, which includes characterizing the functionalities of different moving groups, the variator and the compensator, different types of zoom lens configurations, evolution of zoom types and lastly several novel applications of zoom lenses. In Chapter 3, design of a 7.5x afocal zoom with maximum resolution of 0.68μm is presented. The process starts with finding a thin lens solution, then a monochromatic thick lens solution; finally a diffraction limited polychromatic thick lens solution is achieved. In Chapter 4, a reversed ray trace method is introduced to identify and correct the kernel aberrations in zoom lens. Some patent examples are used to show kernel aberrations with the reversed ray trace method. Then two optimization examples of the kernel aberrations are given at the end. Chapter 5 concludes the work presented in this thesis, with some suggestions for possible future works.