Three–dimensional sensing by using a lenslet, a Dammann grating, and a combination

In the last two decades, three-dimensional sensors based on misfocusing have been suggested. This research addresses the question of measuring several focal depths simultaneously. Two options for generating the necessary array of spots are analyzed: the use of a lenslet array and the use of a Dammann grating. Finally, a combination of the two approaches is proposed. Such a combination enables tailoring the system performance to the exact needs of the user.