A Nonlinear Interferometer for Measurement of 1D and 2D Interferograms in NMR and ESR Spectroscopy

Interferometric concepts in magnetic resonance are known from stochastic NMR spectroscopy.1 There the magnetization is sampled in response to noise excitation and processed after the experiment on a computer by evaluating the Fourier transforms of nonlinear cross-correlation functions. Alternatively the cross- correlation functions can be evaluated by hardware on line during the experiment. A linear correlation function is evaluated in this way by the Michelson interferometer used in FT IR spectroscopy. Nonlinear correlation functions are nonlinear interferograms, which can be evaluated in terms of relaxation decay curves, echoes, and various ID and 2D spectra.