Measuring parameters and characteristics of a fiber optic spectrometer using white-light spectral interferometry

Abstract

Spectral-domain white-light interferometric technique with channeled spectrum detection is used to measure characteristics and parameters of a fiber optic spectrometer. In the experimental setup comprising a white-light source, a Michelson interferometer and a spectrometer to be characterized, the spectral interferograms are recorded for different optical path differences (OPDs) between interfering beams. By processing the recorded spectral interferograms using discrete filtering and fringe amplitude demodulation method, the spectral fringe visibilities, first as a function of wavelength for given OPDs between interfering beams, and second as a function of the OPD between interfering beams for given wavelengths, are obtained. It is confirmed, in accordance with previous experimental and theoretical results, that the spectral fringe visibility functions, which are dependent on the OPD between interfering beams, are Gaussian functions. From the widths of the Gaussian visibility functions the spectrometer bandpasses at different wavelengths are evaluated.