Abstract: The interference pattern of the sodium lamp light and the mercury lamp light is measureed by Michael interference device,using the transformation relations of the interference pattern and the spectra which exist in Fourier spectrum,the sodium lamp and mercury lamp radiation spectrum is analyzed by fast Fourier transform method.The results show that the Fourier transform spectrum can clearly display the radiation spectrum of the radiation source.

Key words: Fourier spectrum, fast Fourier transform, modulation, demodulation