Method of and apparatus for the measurement of mode field radius in single-mode fibres.

摘要

The method of measuring mode field radius in single-mode optical fibres comprises the modulation of an optical beam by means of a spatial filter with radial-distribution of transmittivity of Gaussian type. Modulated beam intensity is measured in correspondence with the beam axis for different widths of the Gaussian curve, and the mode field radius is derived from both such intensity values and a parameter dependant on the Gaussian width. The apparatus which implements the method is also provided.