Open AccessFocus detection criterion for refocusing in multi-wavelength digital holography
Author(s) -
Li Xu,
Mike Mater,
Jun Ni
Publication year - 2011
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.19.014779
Subject(s) - focus (optics) , optics , digital holography , holography , contrast (vision) , computer science , depth of focus (tectonics) , phase (matter) , wavelength , phase contrast microscopy , spatial frequency , artificial intelligence , physics , paleontology , subduction , quantum mechanics , biology , tectonics
The majority of focus detection criteria reported is based on amplitude contrast. Due to phase wrapping, phase contrast was previously reported unsuitable for focus finding tasks. By taking the advantage of multi-wavelength digital holography, we propose a new focus detection criterion based on phase contrast. Experimental results are presented to prove the feasibility of the developed criterion. Possible applications of the developed technology include inspecting machined surfaces in the auto industry.