Two-wavelength interferometry that is based on a Fourier-transform method has been investigated. A phase profile at a synthetic wavelength has been measured from a two-wavelength interferogram with two spatial carrier frequencies. A phase error caused by the difference between modulation intensities at two wavelengths has been theoretically and numerically analyzed. A phase map without the error can be obtained from a power-spectrum adjustment in the two-wavelength interferogram.
© 1998 Optical Society of America
(070.2590) Fourier optics and signal processing : ABCD transforms
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(120.6650) Instrumentation, measurement, and metrology : Surface measurements, figure
Ribun Onodera and Yukihiro Ishii, "Two-Wavelength Interferometry That Uses a Fourier-Transform Method," Appl. Opt. 37, 7988-7994 (1998)