Doppler phase-shift digital holography and two-wavelength interferometry

Abstract

Digital holography utilizing optical Doppler effect is proposed, and the surface shapes of objects are measured in an environment with a disturbance. In this method, the time variation of interference fringes are recorded using a high speed CMOS camera. The complex amplitude of the object beam included in the recorded images are extracted by time-domain Fourier analysis. Light propagation is calculated using the complex amplitude, and the surface shape of the concave mirror is obtained. We also apply the Doppler phase-shift digital holography to two-wavelength interferometry. The phase distribution for the effective wavelength with two different wavalenghes of light sources is obtained. The experimental results show our proposed method is very useful in industrial sensing and experimental mechanics.