Quantitative phase imaging (QPI) is a rapidly emerging field, with several potential applications in biology, material science and experimental mechanics. The main aim of this talk is to introduce the QPI modality, explain its inherent advantages, and highlight the applications in diverse areas. The first part of the talk focuses on digital holography and interferometry, where robust signal processing methods are applied to solve the challenging problems for phase retrieval in QPI. Their application in non-destructive testing and precision metrology would also be discussed. In the second part of the talk, the recently developed QPI techniques based on diffraction phase microscopy (DPM) and spatial light interference microscopy (SLIM) are presented. DPM provides a full-field, compact and extremely stable measuring system for nanoscale topography and dynamic spatial light modulator characterization. Similarly, SLIM enables speckle-free and label-free imaging of biological specimens, and its application for studying the dynamics and morphology of a blood clot is demonstrated. These developments could usher new opportunities in precision engineering and biomedical photonics.
Gannavarpu Rajshekhar is a postdoctoral fellow at the Beckman Institute for Advanced Science and Technology at University of Illinois, Urbana-Champaign. He is a recipient of the Swiss National Science Foundation research fellowship. He obtained a Phd in Photonics from the Swiss Federal Institute of Technology Lausanne (EPFL) in 2012. His research interests include biomedical optics, applied signal processing, non-invasive metrology and 3D imaging.