Micro-Ellipso-Height-Profilometry

Experimental and theoretical inspection of the phase-to-height relation in Fourier transform profilometry.

The measurement of an object's shape using projected fringe patterns needs a relation between the measured phase and the object's height. Among various methods, the Fourier transform profilometry proposed by Takeda and Mutoh [Appl. Opt.22, 3977-3982 (1983)] is widely used in the literature. Rajoub et al. have shown that the reference relation given by Takeda is erroneous [J. Opt. A. Pure Appl. ...

Micro Fourier Transform Profilometry (μFTP): 3D shape measurement at 10, 000 frames per second

Recent advances in imaging sensors and digital light projection technology have facilitated a rapid progress in 3D optical sensing, enabling 3D surfaces of complex-shaped objects to be captured with improved resolution and accuracy. However, due to the large number of projection patterns required for phase recovery and disambiguation, the maximum fame rates of current 3D shape measurement techn...

MICRO SCRATCH DEPTH USING 3 D PROFILOMETRY Prepared by Jorge Ramirez

Self-referenced Surface Profilometry

INTRODUCTION In optical surface metrology the reference surface is usually self-calibrated against the part under test because the errors in the reference are of the same order as those in the part under test. The self-calibration, or “absolute test”, is typically done by making three interferometric measurements, an initial measurement and then two more with the part under test shifted lateral...

Heterodyne moiré surface profilometry.

In this study, a novel moiré fringe analysis technique is proposed for measuring the surface profile of an object. After applying a relative displacement between two gratings at a constant velocity, every pixel of CMOS camera can capture a heterodyne moiré signal. The precise phase distribution of the moiré fringes can be extracted using a one-dimensional fast Fourier transform (FFT) analysis o...