Abstract: One example includes an optical element. The optical element includes a first optical material structure comprising a first index of refraction across a frequency spectrum. The optical element also includes a second optical material structure configured to exhibit an index anomaly corresponding to a change in index of refraction from the first index of refraction to a second index of refraction across a portion of the frequency spectrum and a change from the second index of refraction to the first index of refraction along the frequency spectrum. The optical element further includes a diffractive interface corresponding to a non-planar material contact junction between the first optical material structure and the second optical material structure. The diffractive interface can be configured to manipulate in a predetermined manner an optical beam having an optical path through the diffractive interface and having a frequency in the portion of the frequency spectrum.

Abstract: An out-of-field rejection filter (OFRF) can be used in optical systems to reject stray light. Such optical systems can include cameras, projectors, star trackers, and virtual reality or augmented reality displays. The OFRF can include a converter to convert randomly polarized light to p-polarized light and an angular selectivity layer to select in-field p-polarized light and reject out-of-field p-polarized light. The converter and the angular selectivity layer are configured so as to filter out-of-field light while passing in-field light within a light bandwidth. The angular selectivity layer can be a multilayer film of interleaved materials having alternating permittivity and magnetic permeability properties.

Abstract: A small, ultra-light-weight star tracker for space applications uses an out-of-field rejection filter to reduce the physical size and mass of the star tracker by effectively eliminating the need for a sun shade. The out-of-field rejection filter combines a converter for converting randomly polarized light to p-polarized light with an angular selectivity filter that can reject out-of-field p-polarized light. The underside of the angular selectivity filter can be used to reflect a calibrated light source into the optical path.