OSA's Digital Library

Applied Spectroscopy

Applied Spectroscopy


  • Vol. 52, Iss. 7 — Jul. 1, 1998
  • pp: 974–984

Direct Phase Correction of Differential FT-IR Spectra

M. Shane Hutson and Mark S. Braiman

Applied Spectroscopy, Vol. 52, Issue 7, pp. 974-984 (1998)

View Full Text Article

Acrobat PDF (351 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

  • Export Citation/Save Click for help


Step-scan transient Fourier transform infrared (FT-IR) difference spectra are often measured in an ac-coupled configuration. The resulting differential intensity spectra contain both positive and negative bands. This condition poses problems for direct phase correction by the standard Mertz and Forman methods. Restricting the calculated phase angle to the range [-pi/2, pi/2] was previously shown to fix some of these problems, but we show that the use of a reduced-resolution phase spectrum can produce other artifacts. The effect of reduced resolution is analyzed for a simulated noise-free spectrum and for a measured transient spectrum of a real photochemical system, bacteriorhodopsin. Examination of these results reveals that the Mertz and Mertz Signed methods can produce spectral bands of reduced magnitude and unusual band shape, with considerable amounts of intensity remaining along the imaginary axis after phase correction. However, these errors can be eliminated by self-convolution of the measured interferogram, which doubles all phase angles, prior to smoothing. This procedure removes the potential discontinuities in the phase angle due to sign changes in the differential spectrum. With bacteriorhodopsin, this doubled-angle method for direct phase correction is able to produce a transient spectrum which closely matches that produced by using a separately measured dc interferogram to calculate the phase angle.

M. Shane Hutson and Mark S. Braiman, "Direct Phase Correction of Differential FT-IR Spectra," Appl. Spectrosc. 52, 974-984 (1998)

Sort:  Journal  |  Reset


References are not available for this paper.

Cited By

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited