Enhanced quantitative phase imaging in Mach-Zehnder interferometer-based digital holographic microscopy by modulation of the object illumination with an electrically focus tunable lens

In laser based digital holographic microscopy (DHM) quantitative phase imaging (QPI) is affected by scattering and interference fringes due to internal reflections in the experimental setup. We present a concept for the reduction of such coherence induced disturbances. In our approach, the sample illumination light is modulated by an electrically focus tunable lens while series of digital off-axis holograms are recorded from which subsequently averaged QPI images are calculated. The concept is compatible with Mach-Zehnder interferometer-based off-axis DHM and capable for usage with commercial research microscopes. The performance is illustrated by results from living cells.