Fourier transform spectroscopy method, spectroscopic device, and spectroscopic measurement program that improve spectral resolution and spectral accuracy

A Fourier transform spectroscopy method including a Fourier transform frequency analysis method, for observing a periodical and repetitive phenomenon, the method comprising:

• acquiring a temporal waveform by matching a repetition period of a phenomenon with an observation time window size T for observing a temporal waveform of a phenomenon;
• obtaining a discrete distribution spectrum with a frequency interval equal to a reciprocal of said observation time window size T by a Fourier transform of an acquired time waveform;
• holding the formula fn=n/T true for each plot of said discrete distribution spectrum, with fn as a frequency of each plot and integer n as an order of plot;
• changing said repetition period;
• acquiring a discrete distribution spectrum of a temporal waveform acquired after changing the repetition period;
• and
• superimposing multiple discrete distribution spectra of different repetition periods.

A Fourier transform spectroscopic device for observing a periodical and repetitive phenomenon, the device comprising:

• means for acquiring a temporal waveform by matching a repetition period of a phenomenon with an observation time window size T for observing a temporal waveform of a phenomenon;
• means for obtaining a discrete distribution spectrum with a frequency interval equal to a reciprocal of said observation time window size T by a Fourier transform of an acquired time waveform;
• means for changing said repetition period;
• means for overlaying multiple discrete distribution spectra of different repetition periods;
• wherein each plot of said discrete distribution spectrum is held true for the formula fn=n/T, where fn is a frequency of each plot and integer n is an order;
• and
• the spectral resolution of the acquired discrete distribution spectrum becoming infinitesimal (the spectral resolving power becoming infinite) in a case of an observed phenomenon with the relaxation time being longer than said repetition period, and consequently the spectral accuracy being improved.

A computer storage storing a Fourier transform spectroscopic measurement program for observing a periodical and repetitive phenomenon and for making a computer to function according to steps comprising:

• acquiring a temporal waveform by matching a repetition period of a phenomenon with an observation time window size T for observing a temporal waveform of the phenomenon;
• obtaining a discrete distribution spectrum with a frequency interval equal to a reciprocal of said observation time window size T by a Fourier transform of an acquired time waveform;
• changing said repetition period;
• overlaying multiple discrete distribution spectra with different repetition periods;
• holding fn=n/T true for each plot of said discrete distribution spectrum, with fn being a frequency of each plot and integer n being an order;
• and
• wherein the spectral resolution of the acquired discrete distribution spectrum approaches an infinitesimal value and the spectral resolving power becomes unboundedly large in a case of observed phenomenon with the relaxation time being longer than said repetition period, and the spectral accuracy being improved.