A non-contact and low-cost nanomaterial based fiber-optic sensor is developed for measuring large values of electric currents. The magnetic field, generated by the electric current, changes the refractive index of a liquid in which nanomaterial particles are suspended. The change of refractive index is converted to a change in the intensity of light transmitted in an evanescent field based fibe...

We demonstrate an interferometric fiber-optic bending/nano-displacement sensor based on a plastic dual-core fiber. The light coupled into the two fiber cores is first guided along the fiber, and then reflected by the mirror coated at the fiber end. Reflected light coming out of the fiber produces interference that shifts as the fiber bends. The interference shift is interrogated using a slit an...

In this paper we review recent design methodologies for fully dielectric electro-optic sensors that have applications in non-destructive evaluation (NDE) of devices and materials that radiate, guide, or otherwise may be impacted by microwave fields. In many practical NDE situations, fiber-coupled-sensor configurations are preferred due to their advantages over free-space bulk sensors in terms o...

NASA is applying considerable effort on the development of sensor technology for structural health monitoring (SHM). This research is targeted toward increasing the safety and reliability of aerospace vehicles, while reducing operating and maintenance costs. Research programs are focused on applications to both aircraft and space vehicles. Sensor technologies under development span a wide range...

Fiber optic sensors can be used to monitor deformation and/or the overall integrity of structure components. In this paper, we propose a fuzzy control theory based control principle for sensors, and design a new kind of fiber optic sensor used for Geological monitoring. In order to validate the efficiency of the designed sensor, we simulate a water inrush model in a coal mine, and observe the w...

A novel technique is proposed for measuring the distributed strain and temperature in a fiber with a very high resolution. This technique makes use of the jagged appearance of Rayleigh backscatter traces from a single-mode fiber measured by using a coherent OTDR with a precisely frequency-controlled light source. Our preliminary experiment indicated the possibility of measuring temperature with...