Artificial Intelligence in Digital Holographic Imaging

6Gabor Digital Holographic Microscopy

6.1 Introduction

Direct observations of microscale biophysical processes such as kinematics and the dynamics of live cells require suitable tools to resolve both spatial and temporal scales at proper levels. An available candidate is optical microscopy in which, as the power increases and lateral resolution improves, the field of view and depth of field decrease nonlinearly. For example, increasing the power from 10× to 40× will decrease the theoretical depth of field from 12 to 2 μm, which greatly limits the size of the resolvable volume.

Basically, digital holographic microscopy (DHM) can record a 3D volumetric field on a charge‐coupled device (CCD) plane and later reconstruct it. It can be used to investigate the spatial distribution and velocity of a dense particle cloud with an extended depth. Gabor DHM [1] can be implemented by combining Gabor holography and microscope objective (MO) using the same setup as an optical microscopy in which the light source is replaced with a collimated coherent beam and a sequence of magnified holograms is recorded on a CCD camera. Three‐dimensional fields can be digitally reconstructed from these magnified holograms with a similar resolution to optical microscopy. Gabor DHM allows scientists to analyze particle dynamics by recording a time series of particle traces and the trajectory of biological specimens. This chapter introduces Gabor DHM as a promising tool for measuring particle motions and trajectories ...