Three-dimensional quantitative phase imaging: current and future perspectives

Abstract

ABSTRACT Great effort has been made in the recent past to develop new non-destructive imaging modalities for both two and three dimensional objects, based on the phase properties of a specimen. Quantitative phase tomography (QPT) is a hybrid technique that has been proposed to provide three-dimensional (3D) refractive index (RI) profiling of irregular phase objects by combining transverse phase measurements with traditional tomographic reconstruction techniques. This profiling is accomplished through measurements of sets of projections which are ultimately related to the RI values of the object’s transverse cross-section. Th is is particularly useful for 3D refrac tive index determination of specimens where staining is not appropriate or for materials that cannot be stained and is essential to many applications in photonics and biotechnology. This article reviews recent developments in quantitative phase tomogr aphy as they are presently available and suggests future applications based on current research on the 3D RI. The enabling elements for 3D QPT in the context of four key areas are discussed: the effect of the refractive index of the surrounding matching fluid, spatial resolution, phase accuracy and optimal defo cus. Recent progress and future perspec tives related to each of these areas is presented with regard to various test objects of known optical properties. Keywords: Phase imaging, refractive index, tom ography, three-dimensional microscopy.