Abstracts

In this thesis, quantitative phase imaging (QPI)techniques including 2D and 3D versions are investigated andpresented. With QPI, biophysical and biochemical information oftransparent biological micro-specimens can be measured andquantified. 2D quantitative phase maps of cell samples on the onehand can retrieve morphological shapes, and on the other hand canbe converted to dry mass values, which are important bio-markersfor cell growth studies. By adapting QPI system into an imagecytometer, termed Quantitative phase cytometer (QPC), a largepopulation of ~ 10 HeLa cells were characterized with single-celllevel morphology information and dry mass histogram. Next, in orderto gain more accurate information such as nuclear shape, nucleardry mass, and nuclear-to-cytoplasm volume ratio, 3D tomographicversions of QPI, i.e., tomographic phase microscopy (TPM), wasintroduced, which extended the QPI technique from 2D to 3D inimaging capability. To augment the throughput of TPM system, adigital micro-mirror device (DMD) was used to provide the anglescanning illumination, which significantly boosts the anglescanning speed to the magnitude of kHz. However, this anglescanning method suffers from the diffraction noise caused by thebinary grating pattern, which significantly deteriorates theimaging quality. To solve this problem, a novel dynamic spatialfiltering method was proposed to perfectly eliminate thediffraction noise for DMD based high-speed angle-scanning TPMsystems. In summary, the QPI techniques in 2D and 3D modalitiesprovide a promising quantitative tool for label-freecharacterization of biological samples.Advisors/Committee Members: Peter T.C. So (advisor).