Development of optical frequency-modulated fiber optic interferometric sensor for measuring structural strain

Abstract

Optical frequency modulated fiber optic interferometric sensor is developed to sense the mechanical quantities, such as displacement, strain, force etc. It has been difficult to distinguish the increase and decrease of the mechanical quantities measured by the conventional fiber optic interferometric sensors because their signals only have a sinusoidal wave pattern related to the change of the quantities. In this study, in order to measure the mechanical quantities with the distinction of the changing direction of the quantities, the fiber optic Michelson interferometric sensor is simply constructed by the laser light modulated with saw tooth wave pattern.