Imaging of a vibrating object by Sideband Digital Holography

TL;DR

This paper demonstrates a method using sideband digital holography to quantitatively measure and reconstruct the vibration amplitude and shape of objects with large oscillations, surpassing optical wavelength limitations.

Contribution

It introduces a technique to detect high-order sidebands in digital holography for precise vibration measurement and shape reconstruction of vibrating objects.

Findings

Detected up to 120 sidebands, enabling measurement of large oscillation amplitudes.

Reconstructed the vibration shape from zero intensity points across sidebands.

Achieved quantitative vibration analysis beyond optical wavelength scale.

Abstract

We obtain quantitative measurements of the oscillation amplitude of vibrating objects by using sideband digital holography. The frequency sidebands on the light scattered by the object, shifted by n times the vibration frequency, are selectively detected by heterodyne holography, and images of the object are calculated for different orders n. Orders up to n=120 have been observed, allowing the measurement of amplitudes of oscillation that are significantly larger than the optical wavelength. Using the positions of the zeros of intensity for each value of n, we reconstruct the shape of vibration the object.