High-resolution 3D phase imaging using a partitioned detection aperture: a wave-optic analysis.

Quantitative phase imaging has become a topic of considerable interest in the microscopy community. We have recently described one such technique based on the use of a partitioned detection aperture, which can be operated in a single shot with an extended source [Opt. Lett.37, 4062 (2012)OPLEDP0146-959210.1364/OL.37.004062]. We follow up on this work by providing a rigorous theory of our technique using paraxial wave optics, where we derive fully 3D spread functions for both phase and intensity. Using these functions, we discuss methods of phase reconstruction for in- and out-of-focus samples, insensitive to weak attenuations of light. Our approach provides a strategy for detection-limited lateral resolution with an extended depth of field and is applicable to imaging smooth and rough samples.