Abstract

The real-zero interpolation method is applied to a Fourier-transformed infrared (FT-IR) interferogram. With this method an interferogram is reconstructed from its zero-crossing information only, without the use of a long-word analog-to-digital converter. We installed a phase-locked loop circuit into an FT-IR spectrometer for oversampling the interferogram. Infrared absorption spectra of polystyrene and Mylar films were measured as binary interferograms by the FT-IR spectrometer, which was equipped with the developed circuits, and their Fourier spectra were successfully reconstructed. The relationship of the oversampling ratio to the dynamic range of the reconstructed interferogram was evaluated through computer simulations. We also discuss the problems of this method for practical applications.

© 1992 Optical Society of America

Dynamic range enhancement of Fourier transform infrared spectrum measurement using delta sigma modulation

Kei-ichiroh Minami and Satoshi Kawata
Appl. Opt. 32(25) 4822-4827 (1993)

Computation of a spectrum from a single-beam Fourier-transform infrared interferogram

Avishai Ben-David and Agustin Ifarraguerri
Appl. Opt. 41(6) 1181-1189 (2002)

High-accuracy Fourier transform interferometry, without oversampling, with a 1-bit analog-to-digital converter

Vincent Ricardo Daria and Caesar Saloma
Appl. Opt. 39(1) 108-113 (2000)

Multichannel Fourier-transform infrared spectrometer

Mamoru Hashimoto and Satoshi Kawata
Appl. Opt. 31(28) 6096-6101 (1992)

Stationary Fourier-transform spectrometer

Marja-Leena Junttila
Appl. Opt. 31(21) 4106-4112 (1992)