Calibrated multichannel electronic interferometry for quantitative flow visualization

Abstract

Calibrated multichannel electronic interferometry, a new technique for quantitative flow visualization of transient phenomena, is discussed. This technique uses an interferometer combined with diffraction gratings to generate three phase shifted interferograms simultaneously which are used to perform multichannel phase shifting. The optical system is calibrated with no phase object present using standard piezoelectric phase shifting, and this calibration information is stored as an electro-optic hologram. The calibration information is used along with the three phase-shifted interferograms that exist with a phase object present to perform time-resolved phase shifting. Examples using natural convection and separated flows are presented.