Lateral shearing digital holographic imaging of small biological specimens

A lateral shearing interferometer is used for direct holographic imaging of microorganisms. This is achieved by increasing the shear to be larger than the object size and results in a very simple and inexpensive common-path imaging device that can be easily coupled to the output of an inverted microscope. The shear is created by reflections from the front and back surface of a glass plate. Stability measurements show a standard deviation of the phase measurements of less than 1nm over 8 min. without any vibration compensation. The setup is applied to imaging both microorganisms in a microfluidic channel and red blood cells and reconstructions are presented.