High-speed alternative phase-extraction method for imaging array-coupled binary moiré interferometry.

Abstract

An alternative phase-extraction methodology is presented for high-resolution moiré analysis, in which the projected and imaged pattern is imaged by a charge-coupled device (CCD) array relatively spaced at three pixels per period. The profilometric method uses a photolithographically printed binary pattern with a 33.3% duty cycle symmetrically projected and imaged using telecentric lenses. The resulting surface height map reduces phase error by 33% when compared to conventional sinusoidal projection and extraction methods. The presented system has the ability to resolve surface features with a lateral resolution of <50 μm and a topographical resolution <10 μm.