Patent ID: 6924899

Claim:
A wavefront tilt measurement system for measuring the wavefront tilt of light passing through a transmitting or receiving optical system, the optical system including a primary aperture and internal optical elements defining an optical system focal plane, the measurement system comprising: a light source emitting light from the optical system focal plane towards the internal optical elements such that light from the light source emerges from the primary aperture; a plurality of tilt sensors, wherein: each tilt sensor is disposed adjacent to at least one other tilt sensor and adjacent to the primary aperture to receive light emerging from the primary aperture; each tilt sensor includes a sensor focal plane and a plurality of detector elements, each detector element being disposed within one of plurality of overlapping regions of zero and first order images of light emerging from the primary aperture generated by the tilt sensor at the sensor focal plane; and each tilt sensor comprises: a primary sensor lens disposed to receive light emerging from the primary aperture; a reimaging sensor lens optically coupled to the primary sensor lens; a grating optically disposed between the primary sensor lens and the reimaging sensor lens, wherein the primary sensor lens focuses light onto the grating, the grating generates the overlapping regions, and the reimaging sensor lens images the overlapping regions at the sensor focal plane.