Three-dimensional quantitative phase imaging via tomographic deconvolution phase microscopy

Abstract

The field of three-dimensional quantitative phase imaging (3D QPI) is expanding rapidly with applications in biological, medical, and industrial research, development, diagnostics, and metrology. Much of this research has centered on developing optical diffraction tomography (ODT) for biomedical applications. In addition to technical difficulties associated with coherent noise, ODT is not congruous with optical microscopy utilizing partially coherent light, which is used in most biomedical laboratories. Thus, ODT solutions have, for the most part, been limited to customized optomechanical systems which would be relatively expensive to implement on a wide scale. In the present work, a new phase reconstruction method, called tomographic deconvolution phase microscopy (TDPM), is described which makes use of commercial microscopy hardware in realizing 3D QPI. TDPM is analogous to methods used in deconvolution microscopy which improve spatial resolution and 3D-localization accuracy of fluorescence micrographs by combining multiple through-focal scans which are deconvolved by the system point spread function. TDPM is based on the 3D weak object transfer function theory which is shown here to be capable of imaging "nonweak" phase objects with large phase excursions. TDPM requires no phase unwrapping and recovers the entire object spectrum via object rotation, mitigating the need to fill in the "missing cone" of spatial frequencies algorithmically as in limited-angle ODT. In the present work, TDPM is demonstrated using optical fibers, including single-mode, polarization-maintaining, and photonic-crystal fibers as well as an azimuthally varying CO2-laser-induced long-period fiber grating period as test phase objects.

High-throughput intensity diffraction tomography with a computational microscope

“…1(c)], it leads to measurable intensity contrast difference for phase and absorption features, and allows inversion of both quantities simultaneously. (d) The support of the combined TFs sets the resolution limit of our technique, which can be analyzed following the same framework as [33][34][35][36][37]. Since the forward model relies on the existence of a strongly unscattered field, it is only valid for brightfield measurements.…”

“…We then derive the slice-wise (2D) phase and absorption transfer functions (TF) at different depths for each illumination angle. We show that this framework enables flexible and efficient data acquisition, allowing using arbitrary patterning of the illumination angles and much fewer images required compared to other techniques [9,[33][34][35][36][37]. Our model fully accounts for the interference between the scattered and unscattered fields.…”

“…Naturally, one would prefer a technique capable of leveraging the ubiquitous microscopy platforms with minimal hardware modifications. To this end, there has been a continued interest in intensity-only phase tomography techniques, which perform 3D phase imaging without interferometry [7][8][9][28][29][30][31][32][33][34][35][36][37].…”

“…1). Previous efforts [33][34][35][36][37] formulate the phase-intensity mapping in the 3D Fourier space; this approach unfortunately suffers from stringent sampling requirement for the measurement, resulting in hundreds of defocused images needed in practice. In addition, the reconstruction requires computation and memory intensive 3D deconvolution.…”

High-speed in vitro intensity diffraction tomography

“…Other intensity-based approaches have been explored but often require sample or objective scanning along the axial direction to capture a through-focus intensity stack [31][32][33]. The 3D RI map is then recovered from this image stack using deconvolution algorithms [34,35]. For example, the gradient light interference microscopy [16] achieves 3D imaging of thick biological samples using a differential interference contrast (DIC) through-focus intensity stack.…”