Overview

The optical design process includes a myriad of tasks that the designer must perform and consider in the process of optimizing the performance of an imaging optical system. While we often think primarily of the robustness of the optimization algorithm, reduction of aberrations, and the like, there is much more to do. The designer must be at what we sometimes call "mental and technical equilibrium with the task at hand." This means that he or she needs to be fully confident that all of the following are understood and under control:

• All first-order parameters and specifications such as magnification, focal length, f/number, full field of view, spectral band and relative weightings, and others.

• Assure that the optical performance is being met, including image quality, distortion, vignetting, and others.

• Assure that the packaging and other physical requirements, including the thermal environment, is being taken into account.

• Assure that the design is manufacturable at a reasonable cost based on a fabrication, assembly, and alignment tolerance analysis and performance error budget.

• Consider all possible problems such as polarization effects, including birefringence, coating feasibility, ghost images and stray light, and any other possible problems.

Once every one of these items has been addressed and is at least recognized and understood, we start with the sketch of the system. First, the system is divided into subsystems if possible, and the first-order parameters are determined for each subsystem. For example, if we are to design a telescope with a...