Self-interference digital holographic microscopy for live cell imaging

Abstract

Quantitative digital holographic multi-focus phase imaging enables label-free minimally invasive live cell analysis by high resolution detection of sample induced optical path length changes. However, a drawback of many experimental arrangements for the analysis of living cells with digital holography is the requirement for a separate reference wave which results in a phase stability decrease and the demand for a precise adjustment of the intensity ratio between object and reference wave. Thus, a self interference digital holographic microscopy (DHM) approach was explored which only requires a single object illumination wave. Due to the Michelson interferometer design of the proposed experimental setup two wave fronts with an almost identical curvature are superimposed. This results in a simplified evaluation of the digital holograms. The applicability of the proposed self interference principle is illustrated by results from a technical specimen and living single cells. Furthermore, adherent cancer cells have been analyzed for morphology changes in perfusion chambers due to flow and the refractive index of suspended cells was determined. In summary, the method prospects to be a versatile tool for quantitative phase imaging as simplification is important for the establishment of these methods in live cell analysis.