Hartmann wave-front scanner

A wave-front sensor is described that uses a programmable moving aperture t o scan an incoming wave front. The position of the diffraction spot is reco rded behind an objective lens with a two-dimensional sensor and gives an es timate of the local slope at the aperture position. Then the wave front is reconstructed by processing of the dope data. The device is basically a pro grammable Hartmann wave-front sensor. Compared with a microlens Shack-Hartm ann wave-front sensor, its much longer focal length provides higher resolut ion, although real-time operation is lost. A practical implementation of th e new scanner with a liquid-crystal television as the programmable aperture is presented. (C) 1999 Optical Society of America OCIS codes: 010.7350, 12 0.5050, 230.6120.