We study the phase retrieval (PR) technique using through-focus intensity measurements and explain the dependence of PR on the defocus distance. An optimal measurement plane in the out-of-focus region is identified where the intensity distribution on the optical axis drops to the first minimum after focus. Experimental results confirm the theoretical predictions and are in good agreement with an independent phase measurement.
© 2013 Optical Society of America
Optical Design and Fabrication
Original Manuscript: January 21, 2013
Manuscript Accepted: January 26, 2013
Published: March 5, 2013
Alessandro Polo, Silvania F. Pereira, and Paul H. Urbach, "Theoretical analysis for best defocus measurement plane for robust phase retrieval," Opt. Lett. 38, 812-814 (2013)