Dynamic range enhancement of Fourier transform infrared spectrum measurement using delta sigma modulation.
A method for reconstructing a spectrum from a binary interferogram observed with an Fourier transform IR spectrometer is described. With this method an interferogram is quantized with a 1-bit analog-todigitalconverter with a differentiator and an integrator. This method, called delta sigma modulation, features an oversampling of a signal at a rate much higher than the Nyquist sampling rate. We show experimental examples of IR spectra reconstructed by the method, which demonstrate the potential applications of the method to Fourier transform IR analysis. The results imply that the method may exceed the dynamic range over the one attainable with a conventional Fourier transform spectrometer with an analog-to-digital converter of a finite bit number.
Minami
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Kawata
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