Illumination-Coded Optical Diffraction Tomography

Optical diffraction tomography (ODT) is a label-free 3D light microscopy technique that utilizes refractive index (RI) distributions as a source of image contrast. In ODT, a sequence of 2D holograms is acquired to reconstruct a 3D RI map of a semi-transparent object by using an inverse scattering model. In recent developments, through using spatial light modulators (SLMs), digital micromirror devices (DMDs), or light-emitting diode (LED) arrays, illumination-coded ODT methods have been realized to allow for faster and more stable 3D imaging, opening up many new avenues in both bioimaging and material metrology. In this chapter, we present the principles of ODT that include the reconstruction models and experimental apparatus, review the latest developments in illumination-coded ODT, and highlight several emerging applications of ODT.