Patent ID: 8188411

Claim:
A guidance system, comprising: a non-imaging optical system to focus incident electro-magnetic radiation (EMR) in a detection band including at least one wavelength in a range of 0.35 microns to 15 microns, comprising: a first optical element having a first side and a second side, wherein the first side is a first lens element configured to focus incident EMR; a spreader configured to spatially homogenize EMR transmitted through the optical system; a filter configured to reject EMR including wavelengths outside the detection band; and a second optical element having a first side and a second side, wherein the second side is a second lens element configured to control the aberration characteristics of the EMR transmitted through the optical system; said first optical element, spreader, filter and second optical element optically bonded together in an integrated filter stack having only a first air-to-glass interface at the first side of the first optical element and a second air-to-glass interface at the second side of the second optical element, and an irradiance detector coupled to the optical system and configured to generate at least one guidance signal in response to the spatial displacement of the centroid of the focused incident EMR in the detection band.