Research Progress on Evanescent Wave Sensor Based on Mid-Infrared Optical Fiber

Fiber sensors based on the principle of evanescent waves are widely used in liquid, gas, and biochemical sensors due to their high sensitivity, fast response speed and low cost. Meanwhile, mid-infrared optical fibers based on tellurite glass, fluoride glass, chalcogenide glass and halide crystal have attracted much recent attention in the sensing field because of their wide infrared transmission range. This paper reviewed the principle of mid-infrared fiber optic evanescent wave sensing, introduced the characteristics of various mid-infrared fiber matrix materials, fiber structure and parametric properties, provided a detailed review of its sensing progress in the mid-infrared of gases, liquids, and biochemistry. In addition, the development tendency of mid-infrared optical fiber evanescent wave sensors was also prospected.