The use of a Shack–Hartmann wave-front sensor as a position-sensing device is proposed and demonstrated. The coordinates of a pointlike object are determined from the modal Zernike coefficients of the wave fronts emitted by the object and detected by the sensor. The position of the luminous centroid of a moderately extended incoherent flat object can also be measured with this device. Experimental results with off-the-shelf CCD cameras and conventional relay optics as well as inexpensive diffractive microlens arrays show that axial positioning accuracies of 74 μm rms at 300 mm and angular accuracies of 4.3 μrad rms can easily be achieved.
© 2000 Optical Society of America
(010.7350) Atmospheric and oceanic optics : Wave-front sensing
(120.3930) Instrumentation, measurement, and metrology : Metrological instrumentation
(220.4840) Optical design and fabrication : Testing
Jorge Ares, Teresa Mancebo, and Salvador Bará, "Position and Displacement Sensing With Shack-Hartmann Wave-Front Sensors," Appl. Opt. 39, 1511-1520 (2000)