Dual-interference-channel quantitative-phase microscopy of live cell dynamics.

We introduce and experimentally demonstrate a fast and accurate method for quantitative imaging of the dynamics of live biological cells. Using a dual-channel interferometric setup, two phase-shifted interferograms of nearly transparent biological samples are acquired in a single digital camera exposure and digitally processed into the phase profile of the sample. Since two interferograms of the same sample are acquired simultaneously, most of the common phase noise is eliminated, enabling the visualization of millisecond-scale dynamic biological phenomena with subnanometer optical path length temporal stability.