The use of digital/electronic holography for biological applications

This paper presents the performance of electronic holography for imaging applications of biological and medical interest involving turbid media. It demonstrates that digital holography is useful for biological studies in the areas of estuary sediment erosion and imaging unstained living cells. In particular, we demonstrate the recording geometries of classical 'in-line' back illumination using a collimated beam for measuring micro-particles eroded in a cylindrical observation chamber; we also demonstrate a phase contrast set-up using a magnifying lens for observing biomedical micro-objects of unstained living cells in physiological saline. Practical results are presented for the studies of sediment erosion and transport, which provide information about how polymeric substances produced by the organisms in sediment and erosion shear velocity affect the sediment particle size when erosive stresses are applied to sediment beds.