A phase-evaluation method of multiple-beam Fizeau patterns that combines two-beam phase-stepping algorithms with the moiré effect was previously reported [Appl. Opt. <b>34,</b> 3639–3643(1995)]. The method is based on a multiplicative moiréimage-formation process obtained by the direct superposition of high-frequency multiple-beam Fizeau carrier fringes upon a transmission grating (working as a phase modulator). We present a comparison between this multiplicative moiré two-beam phase-stepping method and the well-known Fourier-transform method for the topographic measurement of an undoped silicon wafer. The discrepancy between the two methods yields a rms phase-difference value of the order of(~2π/90).
© 1998 Optical Society of America
(070.4340) Fourier optics and signal processing : Nonlinear optical signal processing
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.4120) Instrumentation, measurement, and metrology : Moire' techniques
Benito V. Dorrío, Carlos López, José M. Alén, Javier Bugarín, Antonio Fernández, Angel F. Doval, Jesús Blanco-García, Mariano Pérez-Amor, and José L. Fernández, "Multiplicative Moiré Two-Beam Phase-Stepping and Fourier-Transform Methods for the Evaluation of Multiple-Beam Fizeau Patterns: A Comparison," Appl. Opt. 37, 1945-1952 (1998)