Extending the depth of field of integral imaging system by employing cubic phase plate

A cubic non-rotating symmetrical phase plate placed in the pupil of each pickup microlens has been proposed to enlarge the depth of field (DOF) for the imaging system, which is based on a combination of integral imaging and three-dimensional imaging techniques. In the extended depth of the field (EDOF) system, the imaging characteristics of the integral imaging (InI) system with the phase plate or not is analyzed, respectively. With the increase of the defocus, the MTF of the EDOF system changes little and does not appear zero point, the DOF of the microlens unit could be increased more than five times compared to the original one. The result verifies that the use of the cubic phase plate is an effective approach to get a clear imaging.