Patent ID: 7002672
Filing Date: 2006-02-21
Classification: G01B,G01D,G01L,G01M

Abstract:
1. An optical fiber strain sensor device, comprising; an FBG sensor mounted on an object to be measured, a broadband light source for directing a broadband light ray to the FBG sensor, and a filter that both reflects and transmits a light ray reflected from the FBG sensor, means for detecting a change in the wavelength of the light ray reflected from the FBG sensor or a change in the strain of the FBG sensor, including means for detecting an amplitude change in a signal that is obtained by inverting the phase of one of: (a) a signal representative of the light ray reflected from the filter and (b) a signal representative of the light ray transmitted through the filter, and then adding the inverted and non-inverted signals to each other.