We present a new method of phase retrieval from the spectral interferograms, which is based on the use of a windowed Fourier transform applied in the wavelength domain. First, the numerical simulations are performed to demonstrate high precision of the phase retrieval from the spectral data related to a slightly dispersive Michelson interferometer comprising a thin-film structure. Second, the feasibility of the method is confirmed in processing experimental data from the Michelson interferometer with SiO₂ thin film on a silicon wafer to determine precisely the thin-film thickness. We confirm very good agreement with the previous results obtained by the fitting of the recorded spectral interferograms to the theoretical ones. Finally, the method is used in processing experimental data from the Michelson interferometer with two metallic mirrors. From the retrieved phase function, the effective thickness of the beamsplitter made of BK7 glass is determined precisely.

Date Published: 1 May 2008
PDF: 9 pages
Proc. SPIE 6995, Optical Micro- and Nanometrology in Microsystems Technology II, 69950Z (1 May 2008); doi: 10.1117/12.778303

Published in SPIE Proceedings Vol. 6995:
Optical Micro- and Nanometrology in Microsystems Technology II
Christophe Gorecki; Anand Krishna Asundi; Wolfgang Osten, Editor(s)