Transport-of-intensity phase imaging using commercially available confocal microscope

Confocal microscopy is an indispensable tool for biologists to observe samples and is useful for fluorescence imaging of living cells with high spatial resolution. Recently, phase information induced by the sample has been attracting attention because of its applicability such as the measurability of physical parameters and wavefront compensation. However, commercially available confocal microscopy has no phase imaging function. In this Letter, phase imaging based on the transport of intensity equation (TIE) in commercially available confocal microscopy is proposed. The proposed method requires no any modification using a bright field imaging module of a commercially available confocal microscope. The feasibility of the proposed method is confirmed by evaluating the phase difference of a microlens array and living cells of the moss Physcomitrium patens and living mammalian cultured cells. In addition, multi-modal imaging of fluorescence and phase information is demonstrated.