Phase shifting interferometry from two normalized interferograms with random tilt phase-shift

Two-wavelength phase shifting interferometry.

This paper describes a technique that combines ideas of phase shifting interferometry (PSI) and two-wavelength interferometry (TWLI) to extend the phase measurement range of conventional single-wavelength PSI. To verify theoretical predictions, experiments have been performed using a solid-state linear detector array to measure 1-D surface heights. Problems associated with TWLPSI and the experi...

One-Shot Phase-Shifting Interferometry with Phase-Gratings and Modulation of Polarization Using N≥4 Interferograms

Two-step self-tuning phase-shifting interferometry.

A two-step self-tuning phase-shifting method is presented. The phase-step between the two interferograms is not known when the experiment is performed. Our demodulating method finds, in a robust way, this unknown phase-step. Once the phase-step is estimated we proceed to phase demodulate the interferograms. Moreover our method only requires the fringe patterns to have a constant unknown phase-s...

Phase shifter calibration in phase-shifting interferometry.

This paper describes some practical methods to calibrate the phase shifter in phase-shifting interferometry (PSI). The phase shifter used in the experiment is a piezoelectric transducer (PZT) that has a nonlinearity of <l%. Using the quantitative method described in this paper, the repeatability in the measurement of the phase-shifting angle is ̃9.046 rms, and the 3σ value is 0.139. A calibratio...

Phase-Shifting Interferometry for RF Phase Measurement

This paper introduces an interferometric technique for the phase measurement of microwave devices. A handheld vector network analyzer (VNA) is presented for HF and VHF applications. A wideband synthesizer with multiple synchronized outputs is developed for extending the frequency range to the microwave band. The phase differences between the output signals can be set digitally with sub-degree a...