We have recently reported azobenzene-coated fiber Bragg grating (FBG) for ultraviolet (UV) sensor. In this paper, we introduce an etched FBG for the strain sensitivity enhancement of the UV fiber grating sensors, which is inversely proportional to the fiber diameter. The sensitivity of the etched FBG with a diameter of ~60 μm is improved to be greater than twice of the original 125 μm fiber. In addition, the sensor system designed on the basis of the round-trip configuration can be used for many practical sensing applications in the field.
Recently, an ultraviolet (UV) sensor based on a photomechanically responsible material and a fiber Bragg grating (FBG)
has been proposed by our group. The elasticity of the azobenzene polymer as a photo-responsive material is changed by
UV light, which induces a center wavelength shift corresponding to the variation in the azobenzene-coated FBG's period.
In this study, we test the performance and reliability of the abovementioned sensor.