Measurement method of chromatic dispersion of optical beam waveguide using interference fringe measurement system

摘要

The present invention relates to a measurement method of the chromatic dispersion of an optical waveguide using an optical interferometer with a broadband multi-wavelength light source and an optical spectrum analyzing apparatus, wherein one arm, called “reference arm” of the interferometer's two arms has an adjustable air spacing and the other arm, called “sample arm” can contain said optical waveguide to be measured, and including the following measurement and analysis steps: measuring interference spectra of the optical beam output exiting from the said interferometer with an optical spectrum analyzing apparatus when said optical waveguide is connected to said sample arm, and when said optical waveguide is not connected to said sample arm respectively; by adjusting the reference arm length for appearance of clear interference patterns; converting the wavelength-domain interference spectra into frequency-domain interference spectra and calculating phase difference values of the interference peaks of one of the spectra from a predetermined reference peak as a function of the frequency change by counting the interference peak (or valley) points; finding a Taylor series curve fit function for each set of the phase difference value data corresponding to each of the two interference spectra; and calculating a chromatic dispersion coefficient of the optical waveguide by using the coefficients of the Taylor series curve fit functions.