VARIABLE SPREAD CORRECTION MODULE

摘要

PROBLEM TO BE SOLVED: To provide a spread correction module to variably correct the high order spreads by forming temperature distributions in the chirp fiber grating in the long axial direction in a simple configuration. SOLUTION: The variable spread correction module of this invention has a fiber grating 12 and a temperature control means (cooling element 13) to form temperature gradients in the fiber grating 12. The fiber grating 12 has 1st and 2nd sectors alternately arranged in the long axial direction, and each of the 1st sectors periodically changes its refractive index in the long axial direction. The refractive index change in each of the 2nd sectors is smaller than in the 1st sectors. COPYRIGHT: (C)2006,JPO&NCIPI