Multi optical path generator for fiber optic strain sensors multiplexing

A multi optical path generator based on a tunable long Fabry-Perot optical fiber cavity is proposed and demonstrated. It would be used in an optical fiber sensing system which could multiplex a number of fiber sensors with different gauge lengths. Using this optical path generator, we can get a sequence of light beams with different optical paths, which will be coupled to the fiber sensor array in the sensing system. The multi optical path lengths generated by the device are analyzed and discussed. And the relative intensity of the corresponding light beam is calculated. The multiplexing capability caused by the optical path generator is discussed and the experimental results are confirmed this. The system can be used in strain or deformation sensing for smart structure health monitoring.