Raman sensor based on metal-coated hollow-core fiber

In this paper, we have proposed and fabricated a novel Raman sensor with an internal metal-plated hollow-core fiber, and the core device of this sensor is a hollow-core fiber with an internal silver coating. The large aperture diameter of the hollow core fiber with internal metal plating enables fast sample switching, and also allows simultaneous transmission of excitation light and sample, increasing the volume of light-sample interaction to be measured and improving the collection efficiency of Raman signals. The experimental results have shown that the Raman signal is enhanced by a factor of 4.24 using the hollow core fiber with internal metal plating compared with that using the hollow core fiber without internal metal plating, which has the potential of high sensitivity, high stability and on-line detection.