Fourier phase microscopy for investigation of biological structures and dynamics Gabriel Popescu, Lauren P. Def lores, and Joshua C. Vaughan
George R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts 02114
Photonics K.K., Hamamatsu, Shizuoka 430-8587, Japan
Ramachandra R. Dasari and Michael S. Feld
George R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Received May 26, 2004 By use of the Fourier decomposition of a low-coherence optical image field into two spatial components that can be controllably shifted in phase with respect to each other, a new high-transverse-resolution quantitative-phase microscope has been developed. The technique transforms a typical optical microscope into a quantitative-phase microscope, with high accuracy and a path-length sensitivity of l 5500, which is stable over several hours. The results obtained on epithelial and red blood cells demonstrate the potential of this instrument for quantitative investigation of the structure and dynamics associated with biological systems without sample preparation. © 2004 Optical Society of America OCIS codes: 180.0180, 170.1530.
Phase-contrast and differential interference-contrast microscopy provide high-contrast intensity images of transparent biological structures without sample preparation.1,2 However, although these techniques reveal the structure of the sample, the phase information provided is qualitative. Phase-shifting interferometry (PSI) is commonly used for quantitative metrology,3 and interferometric techniques based on this principle have been demonstrated for fast imaging.4 Digital holography has also been developed for phase-contrast imaging5 and integrated with PSI.6 Recently, by...