A new, to the author’s knowledge, method for time-averaged TV
holography measurements of small-amplitude vibrations is
presented. In time-averaged TV holography with sinusoidal phase
modulation of the reference arm of the interferometer, two phasors
describe the object vibration and the modulation of the reference
arm. By inversion of the squared zero-order Bessel function of the
first kind, it is possible to measure the distance between these two
phasors. The distances from an object-vibration phasor to a number
of known reference phasors are measured to determine the amplitude and
the phase of the object vibration. The method is demonstrated by
the measurement of a vibration mode of a circular metal disk. The
results are compared with theoretical data and with data obtained by a
commonly used method in phase-modulated TV holography.
© 1998 Optical Society of America
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