Conformal optical design

Abstract

Optics with external surfaces that deviate from conventional forms to better satisfy the needs of host platform are known as conformal optics. These external surfaces generate significant amounts of aberration that may be compensated with additional corrector elements. This dissertation introduces a new tool for the design of correctors for non-rotationally symmetric optical systems. This is accomplished through the derivation of two new differential equations using an approach similar to that of Wassermann and Wolf. The new aspheric design equations are derived without the assumption of axial symmetry and may be used to precisely control a ray bundle. Solving the new design equations produces the surface profiles of two aspheric optical surfaces which make a non-rotationally symmetric system aplanatic. The aplanatic system may contain tilted and decentered elements, or optical elements without rotational symmetry before and after the two aspheric surfaces. As coma and spherical aberration can be significant in conformal windows, these equations are powerful for producing starting points and developing a design. To validate the new equations, they were implemented in a Code V RTM macro called the Generalized Aspheric design Program (GAP). This macro is used in the design of a variety of non-rotationally symmetric optical systems to create a diffraction limited field of view. These include a system with an elliptical dome with a decentered inside surface, a system containing cylindrical elements, and a system with a toroidal conformal window. In all cases, GAP is able to directly generate corrector surfaces. For comparison, the classical Wassermann-Wolf equations were also implemented in a Code V macro for the design of rotationally symmetric systems.