OPTICAL FREQUENCY DOMAIN REFRACTOMETRY DEVICE AND OPTICAL FREQUENCY DOMAIN REFRACTOMETRY METHOD

摘要

PROBLEM TO BE SOLVED: To provide an optical frequency domain refractometry device and an optical frequency domain refractometry method with which it is possible to improve the accuracy of measuring strain or temperature distribution over the wide range of an optical fiber being measured.;SOLUTION: Weight filters 61, 62 consist of a weight characteristic A that changes linearly, in which a position between minimal positions z₁, z₂ on an optical fiber being measured where the error of a signal whose linearity of wavelength sweep has been corrected is minimal is a variable, and a weight characteristic B in which a position outside of the minimal positions z₁, z₂ on the optical fiber being measured is a variable. The differential value of amplitude of the weight characteristic B relative to a position on the optical fiber being measured is continuous with the differential value of amplitude of the weight characteristic A at the minimal positions z₁, z₂ and is zero at a position on the optical fiber being measured that corresponds to the zero frequency of a measured interference signal, and is zero at a position on the optical fiber being measured that corresponds to a half of a sampling frequency in linearization means 51, 52.;SELECTED DRAWING: Figure 1;COPYRIGHT: (C)2019,JPO&INPIT