We describe a new scanning microscopy technique, phase-dispersion microscopy (PDM). The technique is based on measuring the phase difference between the fundamental and the second-harmonic light in a novel interferometer. PDM is highly sensitive to subtle refractive-index differences that are due to dispersion (differential optical path sensitivity, 5 nm). We apply PDM to measure minute amounts of DNA in solution and to study biological tissue sections. We demonstrate that PDM performs better than conventional phase-contrast microscopy in imaging dispersive and weakly scattering samples.
© 2000 Optical Society of America
(040.2840) Detectors : Heterodyne
(110.0180) Imaging systems : Microscopy
(110.4500) Imaging systems : Optical coherence tomography
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(170.3880) Medical optics and biotechnology : Medical and biological imaging
Changhuei Yang, Adam Wax, Irene Georgakoudi, Eugene B. Hanlon, Kamran Badizadegan, Ramachandra R. Dasari, and Michael S. Feld, "Interferometric phase-dispersion microscopy," Opt. Lett. 25, 1526-1528 (2000)