An Optical Fiber Thermal Anemometer with Full Light Reflection

An optical fiber thermal anemometer using laser-heated Fabry-Perot interferometer(FPI) is proposed. FPI is manufactured at the tip of germanium-doped fiber using a UV-curing adhesive. The pump light source is the heating light source, and the broadband light source is the detection light source. The interference spectrum of FPI changes with the change of wind speed, and the change of FPI cavity length is not only thermal expansion and contraction caused by temperature, but also strain caused by wind, so we determine the specific value of wind speed by detecting the drift of the interference spectrum. Through experiments, the sensitivity of the low-speed region can reach - 4.27nm/(m ● s
^{- 1}
), and the sensitivity of the high-speed region in the measurement range of 0-8m/s is also stable at -0.14nm/(m ● s-1).