Abstract: Methods and apparatus for a structure function monitor provide for generation of parameters characterizing a refractive medium. In an embodiment, a structure function monitor acquires images of a pupil plane and an image plane and, from these images, retrieves the phase over an aperture, unwraps the retrieved phase, and analyzes the unwrapped retrieved phase. In an embodiment, analysis yields atmospheric parameters measured at spatial scales from zero to the diameter of a telescope used to collect light from a source.

Abstract: An optical system resembling a modified Gregorian astronomical telescope is disclosed in the specification and drawings. Lenses are used in the inter-focal region to modify the optical characteristics of the system. The use of such inter-focal lenses, can, for example, flatten the image plane of the field thereby increasing the field of view of the telescope.

Abstract: A wide field of view telescope having two concave and two convex reflective surfaces, each with an aspheric surface contour, has a flat focal plane array. Each of the primary, secondary, tertiary, and quaternary reflective surfaces are rotationally symmetric about the optical axis. The combination of the reflective surfaces results in a wide field of view in the range of approximately 3.8° to approximately 6.5°. The length of the telescope along the optical axis is approximately equal to or less than the diameter of the largest of the reflective surfaces.

Abstract: An optical system comprising a concave primary mirror reflects light through an intermediate focus to a secondary mirror. The secondary mirror re-focuses the image to a final image plane. Optical limiter material is placed near the intermediate focus to optically limit the intensity of light so that downstream components of the optical system are protected from intense optical transients. Additional lenses before and/or after the intermediate focus correct optical aberrations.

Abstract: A MISFET device which typically utilizes silicon dioxide as an insulating material and which becomes inoperative under ionizing radiation conditions can be made to significantly enhance its radiation survivability by introducing crystalline zinc sulfide as an insulating material. The invention may be manufactured as one of three variations. Crystalline zinc sulfide may replace silicon dioxide as the gate insulator, the field insulator, or both the gate and field insulators.