| 摘要 |
A Fourier transform spectrometer for conducting Fourier transform spectroscopy. The spectrometer has a light source emitting light to a sample via a rapid scan interferometer. The transmittance of the sample varies when stimulated. A stimulus generator gives a stimulus to the sample at regular intervals of tau . A delay circuit produces a trigger delayed with respect to each stimulation to control a gate circuit. Radiation emanating from the sample is detected by a detector. The output signal from this detector is gated onto a low-pass filter after a given delay DELTA tau with respect to each stimulation by the gate circuit. The gate circuit produces a digital interferogram. The low-pass filter passes only those frequency components which satisfy the condition: f<1/2 tau where f is the frequency at which the radiation is modulated by the interferometer. The analog output signal from the filter is converted into digital form by an A/D converter to obtain an interferogram. The interferogram is phase compensated and Fourier-transformed by a computer to derive a spectrum.
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