Showing papers on "Fourier transform infrared spectroscopy published in 1973"
TL;DR: In this article, the water vapour spectrum recorded with a resolution of 5 × 10-3 cm-1 between 2930 cm 1 and 4255 cm 1 on a Fourier transform spectrometer is presented.
Abstract: The water vapour spectrum recorded with a resolution of 5 × 10-3 cm-1 between 2930 cm-1 and 4255 cm-1 on a Fourier transform spectrometer is presented. Wavenumbers, attributions and equivalent widths of about 1500 lines are given. Lines of the 2v 2, v 1 and v 3 bands of H2 16O, lines of the hot band v 2 + v 3 - v 2 of H2 16O and lines of the v 1 and v 3 bands of H2 18O and H2 17O are observed.
116 citations
TL;DR: In this article, a Michelson interferometer for amplitude and phase Fourier spectroscopy in the infrared is described, which allows the determination of the optical constants n and k of relatively small crystal samples at high resolution and low temperatures.
43 citations
TL;DR: In this article, a commercial interferometer has been modified for high resolution gas phase work by adding a variable temperature cell of 3 m path length, and the data reduction method is described, and examples of the performance are given.
Abstract: A commercial interferometer has been modified for high resolution gas phase work by addition of a variable temperature cell of 3 m path length. The data reduction method is described, and examples of the performance are given. Two rotation-vibration bands of diacetylene, ν9 and ν7-ν9, have been analyzed to yield ν9=220.139(5), ν7=482.13(1), and B0 = 0.14649(7) cm-1.
32 citations
26 citations
TL;DR: In this paper, high resolution 113Cd n.m.r. signals have been obtained in the pulse Fourier transform mode for a few representative species; typical relaxation times and the high sensitivity of the chemical shift parameter make 113cd a promising nuclide for detailed studies of complexation in solution.
Abstract: High resolution 113Cd n.m.r. signals have been obtained in the pulse Fourier transform mode for a few representative species; typical relaxation times and the high sensitivity of the chemical shift parameter make 113Cd a promising nuclide for detailed studies of complexation in solution.
26 citations
24 citations
TL;DR: In this paper, the entire spectrum to be analyzed is incident upon the detector from the two interfering beams to take advantage of all of the energy available and then computations are made to display the spectrum.
Abstract: Until recently, infrared spectroscopy has been performed with spectrometers utilizing filtered broadband sources and gratings or prisms to spatially spread the energy spectrum of the source. These wavelength measuring spectrometers characteristically have large spectral tuning ranges with resolutions typically limited to 0.1–1 cm−1: In the far-infrared region where only small amounts of energy are available from broadband sources, two-beam interferometric techniques have been employed with computing techniques to perform Fourier transform spectroscopy. In this technique the entire spectrum to be analyzed is incident upon the detector from the two interfering beams to take advantage of all of the energy available and then computations are made to display the entire spectrum.
23 citations
23 citations
22 citations
TL;DR: The design and tests of an all-reflection two-beam interferometer, which eliminates the need for a transmitting beam splitter and compensation plate, and can be used as a Fourier transform spectrometer, are described.
Abstract: This paper describes the design and tests of an all-reflection two-beam interferometer. The interferometer consists of three reflecting diffraction gratings and two collimating mirrors. The use of only reflection optics eliminates the need for a transmitting beam splitter and compensation plate thus permitting the possibility of using the interferometer in the vacuum ultraviolet. This instrument can be used as a Fourier transform spectrometer. Obtaining the spectrum of the incident light from the interferogram is not so straightforward as with a Michelson interferometer. The method of Fourier inversion is described, and examples of interferograms taken with the instrument and the spectra obtained from the interferograms are presented. The interferometer has been tested in the visible and in the near ultraviolet at 2537 A.
18 citations
TL;DR: In this article, the authors consider a milder restriction: it is only required of the spectrum that it be smaller than the whole rc-space, i.e., the support of its distributional Fourier transform.
Abstract: Introduction. In harmonic analysis, it is important to know how various properties of a function on R reflect themselves as restrictions on its spectrum, i.e., the support of its (distributional) Fourier transform. Thus, according to Paley and Wiener, a compact spectrum is characteristic of entire functions of exponential type. In this note we consider a milder restriction : it is only required of the spectrum that it be smaller than the whole rc-space. Our results extend those of Levinson, Logan, Ehrenpreis and Malliavin ; cf. also Boas [1]. Here we give only bare outlines of proofs ; we employ standard vector notations : t = (tl9..., tn) and x = (xu ... xn) are points of R and (t, x) denotes £ \" tjXji \\t\\ = (t, t), and at denotes Haar measure on R. 1. A gap in a distribution on R is a nonvoid open ball disjoint from its support. A spectral gap in a tempered distribution is a gap in its Fourier transform. In particular, an L function ƒ has a spectral gap if its Fourier transform ƒ (x) vanishes on some nonvoid open set. Such ƒ cannot decay too rapidly, by virtue of the following result of N. Levinson.
TL;DR: In this paper, the infrared spectra of aqueous solutions of electrolytes and nonelectrolytes were recorded using a Fourier transform spectrometer, where the presence of solutes affects the absorption of water, so that spectra show distortions of the background in the vicinity of the water stretching and deformation bands.
TL;DR: For some years now, a number of research laboratories have been interested in obtaining the far infrared spectra of matrix-isolated molecules as mentioned in this paper, which can be critical in the determination of the molecular structure and consequently the accuracy of thermodynamic functions which are determined.
Abstract: For some years now, a number of research laboratories have been interested in obtaining the far infrared spectra of matrix-isolated molecules. High temperature chemists, for example, have been concerned with observing low frequency vibrational motions of a variety of species generated from Knudsen ovens. The observation of these low frequency (bending) modes can be critical in the determination of the molecular structure and consequently the accuracy of thermodynamic functions which are determined. This application has been the subject of a recent review. Other areas of interest requiring the use of far infrared techniques include the study of the pure rotational spectra of matrix-isolated hydrogen halides, the study of impurity-induced lattice modes in molecular crystals, and the study of transition metal halides.
TL;DR: In this paper, the effect of varying the groove depth of a lamellar grating illuminated by a plane wave at near-normal incidence is investigated and a critical re-evaluation is performed.
TL;DR: In this article, the optical analogue computer and coherent optical Fourier transformation of asymmetric interferograms are discussed in terms of transparent variable area masks with amplitude transmittance ± 1.
TL;DR: In this paper, a method of modifying the mirror drive mechanism in a commercial Fourier transform spectrometer in order to double the resolution is described, and the comparison of the two spectra is given.
Abstract: A description is given of a method of modifying the mirror‐drive mechanism in a commercial Fourier transform spectrometer in order to double the resolution. Comparative spectra are given which were taken before (resolution ≈ 0.050 cm−1) and after the modification (resolution ≈ 0.026 cm−1).
TL;DR: An assembler language program for a PDP 11 20 (1) computer has been written for on-line data acquisition and analysis of asymmetric interferograms obtained by far infrared Foutier transform spectroscopy as discussed by the authors.
01 Jun 1973
TL;DR: In this paper, the effect of input source varia-tions during the time of the measurement interval is analyzed in relation to transform spectrometry, both over-all and relative spectral changes are considered.
Abstract: The effect of input source varia-tions during the time of the measurement interval is analyzed in relation to transform spectrometry. Both over-all and relative spectral changes are considered. Hadamard and Fourier transform spectrometry are used as examples. The Fourier spectrometer (interferometer) is shown to be capable, after correction, of generating the mean value of the input spectrum over the measurement interval, while the so-called "Hadamard" spectrometer fails to do so. These conclusions are demonstrated experimentally using synthetic spectra.© (1973) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.