Holographic optical element based digital holographic interferometer for label-free imaging of staphylococcus aureus bacteria

Staphylococcus aureus (S. aureus) is a round-shaped, aggressive human pathogen that can grow either by fermentation or by utilizing an elective terminal electron acceptor without oxygen. These bacteria can spread from an infected person to others, and it can enter into the body via the bloodstream and can infect body parts and organs. To avoid spreading infections and life-threatening diseases, a rapid, non-invasive, non-contact expeditious detection system is required. In this paper, a holographic optical element based digital holographic interferometric (DHI) system has been demonstrated for the label-free imaging of S. aureus bacteria. A comparison has been made in the proposed holographic optical element based DHI system and the conventional off-axis Mach–Zehnder configuration based DHI system. The proposed DHI system is an economical, efficient and easy-to-operate interferometric system, and significantly improves the signalto- noise ratio of recorded digital holograms without any spatial filtering.