FOURIER TRANSFORM SPECTROMETER, FOURIER TRANSFORM SPECTROSCOPY AND ATTACHMENT FOR FOURIER TRANSFORM SPECTROMETER

PROBLEM TO BE SOLVED: To provide a new wavelength calibration technique, more specifically, a Fourier transform spectroscopic technique capable of performing wavelength calibration with higher accuracy.SOLUTION: A Fourier transform spectrometer of the present invention performs wavelength calibration using emission line spectrum, however, center burst position is not easily detected by using only the emission line spectrum. In order to obtain an emission line spectrum, a first spectrum is obtained with respect to emission line light having an emission line spectrum including one or more emission lines and bias light having a continuous spectrum, and a second spectrum with respect to only the bias light is obtained. Then, a difference between the first spectrum and the second spectrum is obtained to thereby obtain the emission line spectrum of the emission line light. The wavelength calibration is performed based on emission line peaks included in the emission line spectrum thus obtained.