Imaging Fourier spectrometer in visible domain: experimental results

Performance of a prototype of a compact imaging Fourier spectrometer for visible domain is reported. In high-frequency applications up to 100 MHz, the optical signal is recorded by a photo-multiplying tube. Selectivity of spectra modulated at 100 kHz on the background of non-modulated light and possibility of measuring 50 ns decay time of molecular transitions is experimentally demonstrated. On line-type spectra with the same exposure time and spectral resolution, the imaging Fourier spectrometer may be 10 times more sensitive than the best compact grating spectrometers. This superiority disappears on smooth spectra with short coherence length. In visible and near-infrared domains, a carefully made prototype of an imaging Fourier spectrometer with a photo-multiplying tube proves to be sensitive to as low optical flux as 6⋅10^-13W/mm².