Abstract

An adaptive imaging telescope having nonlinear sensing means for detecting an optical image received thereby. The system comprises a phase shifter, positioned at the aperture of the telescope or at an image plane thereof. This system also includes a nonlinear image quality sensor optically coupled to the phase shifter, consisting of a quadrant nonlinear detector wherein each detector element of the quadrant detector is responsive to light from the optical image, the quadrant detector comprising nonlinear photocells or detectors whose plane is positioned at an image plane of the telescope. The photocells are connected to a network for providing image quality error signals. Analog circuits are provided to receive the sensor output and provide a closed-loop return to the phase shifter.