LAURENZIS M ET AL: 'LONG-RANGE THREE-DIMENSIONAL ACTIVE IMAGING WITH SUPERRESOLUTION DEPTH MAPPING', OPTICS LETTERS, OPTICAL SOCIETY OF AMERICA, vol. 32, no. 21, 1 November 2007 (2007-11-01), pages 3146 - 3148, XP001509613, ISSN: 0146-9592, DOI: 10.1364/OL.32.003146