Conformal optics technology enables window shapes that conform to an application, not to conventional optical limitations.
Robert R. Shannon, James P. Mills, Harvey M. Pollicove, Patrick A. Trotta and L.N. Durvasula
The optical dome conventionally used on the front end of a missile is a section of a sphere, because spherical optical design and fabrication are well-understood. Such blunt forms, however, produce considerable aerodynamic drag.
Replacing a spherical front end with a more aerodynamically efficient form, such as an ellipsoid, significantly increases speed or range for a given amount of propulsion energy expended...