Open AccessVirtual optics and sensing of the retrieved complex field in the back focal plane using a constrained defocus algorithm
Author(s) -
Mengqi Shen,
Terry W.K. Chow,
Hong Shen,
Michael Geoffrey Somekh
Publication year - 2020
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.404573
Subject(s) - cardinal point , phase retrieval , optics , plane (geometry) , computer science , phase (matter) , image plane , plane wave , field (mathematics) , focal length , algorithm , physics , computer vision , image (mathematics) , fourier transform , mathematics , geometry , quantum mechanics , pure mathematics , lens (geology)
The reflected back focal plane from a microscope objective is known to provide excellent information of material properties and can be used to analyze the generation of surface plasmons and surface waves in a localized region. Most analysis has concentrated on direct measurement of the reflected intensity in the back focal plane. By accessing the phase information, we show that examination in the back focal plane becomes considerably more powerful allowing the reconstructed field to be filtered, propagated and analyzed in different domains. Moreover, the phase often gives a superior measurement that is far easier to use in the assessment of the sample, an example of such cases is examined in the present paper. We discuss how the modified defocus phase retrieval algorithm has the potential for real time measurements with parallel image acquisition since only three images are needed for reliable retrieval of arbitrary distributions.