Transport of intensity equation: a new approach to phase and light field
Date of Issue2014
SPIE/COS Photonics Asia
School of Mechanical and Aerospace Engineering
Centre for Optical and Laser Engineering
Phase is an important component of an optical wavefield bearing the information of the refractive index, optical thickness, or the topology of the specimen. Phase retrieval is a central problem in many areas of physics and optics since the phase of a wavefield is not accessible directly. The most well-established method for obtaining quantitative phase is through interferometry, such as digital holography. However, this class of methods relies on coherent illumination, therefore, plagued with problems of speckle that prevent the formation of high quality images. On a different note, quantitative phase can be retrieved by transport-of-intensity equation (TIE) using only object field intensities at multiple axially displaced planes. TIE has been increasingly investigated during recent years due to its unique advantages over interferometric techniques: it is non-interferometric, works with partially coherent illumination, computationally simple, no need to phase unwrapping, and does not require a complicated optical system. In this paper, we will review some recent new developments in TIE phase retrieval: including its numerical solution, treatment of boundary problem and the low-frequency artifacts, and configurations for dynamic phase imaging. We also reexamine TIE in terms of phase-space optics, demonstrating the effect of partially coherent illumination on phase reconstruction, and connecting it to light field imaging at the geometry optics limit.
Proceedings of SPIE - Holography, Diffractive Optics, and Applications VI
© 2014 Society of Photo-optical Instrumentation Engineers (SPIE). This paper was published in Proceedings of SPIE - Holography, Diffractive Optics, and Applications VI and is made available as an electronic reprint (preprint) with permission of Society of Photo-optical Instrumentation Engineers (SPIE). The published version is available at: [http://dx.doi.org/10.1117/12.2071713]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.