Objective optics with interference filter

Abstract

Optical apparatus includes an image sensor and an optical assembly, which is configured to focus optical radiation via an aperture stop onto the image sensor. The optical assembly includes a plurality of optical surfaces, consisting of a first, curved surface through which the optical radiation enters the assembly, a final surface through which the rays exit the assembly toward the image sensor, and at least two intermediate surfaces between the first and final surfaces. An interference filter, which has a center wavelength and a passband no greater than 4% of the center wavelength, and includes a coating formed on one of the optical surfaces. All rays of the optical radiation passing through the aperture stop are incident on the coating over a range of incidence angles with a half-width that is no greater than three fourths of the numerical aperture of the optical assembly.

Dependencies are inferred from the claim text.