A system for tomographic imaging includes a source of at least partially
coherent radiation, a frequency-swept laser source and an interferometer.
The radiation in the interferometer is phase modulated at a modulation
frequency for elimination of DC and autocorrelation noises as well as the
mirror image. The interference fringes of the radiation backscattered
from the sample into the interferometer are detected to obtain a spectral
signal. The spectral signal of the detected backscattered interference
fringes is transformed to obtain a location dependent signal at each
pixel location in a data window. A tomographic image of the fluid flow in
the data window is generated for display and of the structure of the
scanned fluid flow sample in the data window from the location dependent
signal is generated.