White light interferometry is a widely used tool to extend the unambiguous measurement range of a monochromatic interferometer. In this work, we discuss Hilbert transformation analysis of a single white light interferogram acquired with a single-chip color CCD camera for step height measurement which lies beyond the unambiguous range of the monochromatic interferometry. The color interferogram is decomposed and phase maps for red, green, and blue components are calculated independently using Hilbert transformation. This procedure makes the measurement faster, simpler, and cost-effective. The usefulness of the technique is demonstrated on micro-sample.

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Single wavelength TV holography is a widely used whole-field noncontacting optical method for nondestructive testing (NDT) of engineering structures. However, with a single wavelength configuration, it is difficult to quantify the large amplitude defects due to the overcrowding of fringes in the defect location. In this work, we propose a two wavelength microscopic TV holography using a single-chip color charge-coupled device (CCD) camera for NDT of microspecimens. The use of a color CCD allows simultaneous acquisition of speckle patterns at two different wavelengths and makes the data acquisition as simple as that of the single wavelength case. For the quantitative measurement of the defect, an error compensating eight-step phase-shifted algorithm is used. The design of the system and a few experimental results on small-scale rough specimens are presented. © 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)

White light single-shot interferometry with colour CCD camera for optical inspection of microsystems Upputuri,

Single wavelength microscopic speckle interferometry is widely used for deformation, shape and non-destructive testing (NDT) of engineering structures. However the single wavelength configuration fails to quantify the large deformation due to the overcrowding of fringes and it cannot provide shape of a specimen under test. In this paper, we discuss a two wavelength microscopic speckle interferometry using single-chip colour CCD camera for characterization of microsamples. The use of colour CCD allows simultaneous acquisition of speckle patterns at two different wavelengths and thus it makes the data acquisition as simple as single wavelength case. For the quantitative measurement, an error compensating 8-step phase shifted algorithm is used. The system allows quantification of large deformation and shape of a specimen with rough surface. The design of the system along with few experimental results on small scale rough specimens is presented.