Optical diffraction tomography using a digital micromirror device for stable measurements of 4-D refractive index tomography of cells

TL;DR

This paper presents a stable optical diffraction tomography system using a digital micromirror device to accurately measure 3-D and 4-D refractive index maps of live cells, enhancing biological imaging capabilities.

Contribution

The study systematically evaluates the precision and stability of DMD-based ODT and demonstrates its application to various live cells for 3-D and 4-D RI mapping.

Findings

High stability and precision in 3-D RI measurements

Successful visualization of RI maps and gradients of live cells

Effective 4-D RI tomography of biological samples

Abstract

Optical diffraction tomography (ODT) is an interferometric microscopy technique capable of measuring 3-D refractive index (RI) distribution of transparent samples. Multiple 2-D holograms of a sample illuminated with various angles are measured, from which 3-D RI map of the sample is reconstructed via the diffraction theory. ODT has been proved as a powerful tool for the study of biological cells, due to its non-invasiveness, label-free and quantitative imaging capability. Recently, our group has demonstrated that a digital micromirror device (DMD) can be exploited for fast and precise control of illumination beams for ODT. In this work, we systematically study the precision and stability of the ODT system equipped with a DMD and present measurements of 3-D and 4-D RI maps of various types of live cells including human red blood cells, white blood cells, hepatocytes, and HeLa cells. Furthermore, we also demonstrate the effective visualization of 3-D RI maps of live cells utilizing the measured information about the values and gradient of RI tomograms.