Pii: 0022-2364(73)90076-0
نویسنده
چکیده
In Fourier spectroscopy, the absorption mode spectrum V(f) and the dispersion mode spectrum U(f) are computed from the experimentally measured impulse response /z(t). Clearly, this general principle must be applicable here as well. Some consequences of practical importance will be discussed in this paper. In practical Fourier spectroscopy a periodic pulse sequence is used to excite the spin system for reasons of sensitivity. It is shown in the section on periodic pulse excitation that, in general, the computed absorption and dispersion mode signals are no longer related. But, based on a modified impulse response supplemented by a period of equal length but with zero amplitude, it is possible to obtain absorption and dispersion mode spectra which are related by a discrete Hilbert transform (the latter was introduced in, Ref. (4)). Practical realizations of Fourier spectroscopy require a discrete representation of the impulse response by a finite number of sample values. Here, the discrete periodic
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