Moiré pattern

About: Moiré pattern is a research topic. Over the lifetime, 1917 publications have been published within this topic receiving 27176 citations. The topic is also known as: moiré fringes & moire pattern.

Moire interferometer with overlapping illumination and imaging systems

Abstract: A moire interferometer has an illumination system and an imaging system that share a common focusing optic, which preferably takes the form of a concave mirror. Within the illumination system, the common focusing optic collimates light en route to a test surface. Within the imaging system, the common focusing optic telecentrically images a grating pattern appearing on the test surface onto a fringe pattern detector.

Single-shot phase-shifting digital holography based on the spatial carrier interferometry

Abstract: Phase-shifting digital holography which is available simply with single-shot exposure of holograms without any special phase-shifting device is proposed. A key point of the present method is phase-shifting property in three or four moire patterns obtained from single holograms with a large spatial carrier by sampling sparsely in a computer. Theoretical analysis is performed for demonstrating the phase-shifting property of these sparsely-sampled hologram patterns from the single hologram. Limits of a carrier frequency, i.e., amount of tilting angle of the reference plane wave used in recording holograms, and a phase slope of the object wave to be reconstructed are also given by theoretical analysis. Numerical simulations are conducted for demonstrating the validity and the limits of the proposed method.

Computer-generated moiré profilometry based on fringe-superposition

Abstract: A computer-generated moire profilometry based on algebraic addition instead of algebraic multiplication is proposed. Firstly, the two AC components of the captured fringe patterns on the reference plane with [Formula: see text] phase difference are retrieved and saved in advance. While measuring, two sinusoidal gratings with [Formula: see text] phase difference are projected onto the measured object alternatively, and the corresponding deformed patterns are captured. Then the AC component of the captured deformed pattern can be separated exactly. When the positive and negative AC component of the captured deformed pattern are added to the two prestored AC components respectively, two moire fringes only reflect sine and cosine of the object's phase information can be successfully generated via a series of data processing procedures. Finally, the phase distribution of the measured object can be extracted by arctangent of the ratio of these two moire fringes. Compared with computer-generated moire profilometry based on algebraic multiplication, this proposed method can reduce the effect of high frequency noise and residual DC component on measurement and improve the measurement accuracy. While compared with [Formula: see text] phase shifting FTP, this method can measure more complex objects with better measurement capability. Experimental results verify the feasibility and validity of the proposed method.

Phase-Measuring Moiré Topography

Abstract: A number of full-field optical methods which exploit interferometric, holographic, speckle or moire fringe phenomena have been developed for the measurement of surface form and deformation. Between them, these methods offer a wide range of sensitivities together with the ability to visualize the quantity of interest through a fringe pattern which describes the height or deformation contours of the surface.