Patent ID: 8503074
Filing Date: 2013-08-06
Classification: G02B

Abstract:
1. A multi-wavelength band imaging system comprising: an objective system which is arranged to collect radiation emanating from an object space; a beam splitter which is arranged to collect radiation from the objective system, split the radiation into radiation in a first wavelength band and radiation in a second wavelength band, and to direct radiation in the first wavelength band to a first image plane and radiation in the second wavelength band to a second image plane; first and second image sensors respectively arranged in the first and second image planes; and a positively powered refractive optical component having a useful spectral bandpass in the first and second wavelength bands; wherein, the objective system includes a convex reflective surface and a concave reflective surface mutually spaced along an optical axis through the beam splitter, the convex reflective surface being disposed to collect radiation from object space and to deliver the collected radiation to the concave reflective surface, and the concave reflective surface being disposed to transfer radiation collected from the convex reflective surface to the beam splitter past the convex reflective surface; wherein the positively powered refractive optical component is optically between the concave reflective surface and the beam splitter; wherein the first image sensor is adapted for imaging radiation in the first wavelength band, the second image sensor is adapted for imaging radiation in the second wavelength band, the first and second wavelength bands being either side of a wavelength of about 2.7 microns; and wherein the first wavelength band is from visible to near infrared and the second wavelength band is intermediate infrared, far infrared or both.