높은 선팽창계수를 가진 재료가 적용된 광섬유격자 온도센서의 민감도 향상에 관한 연구

Abstract

This study reports sensitivity enhancement method of a temperature sensor based on fiber Bragg grating (FBG) in combination with an auxiliary materials with a higher thermal expansion property. We prepared FBG sensor modules attached on both sides of material blocks such as metals or polymers with different thermal expansion coefficients. Subsequently, we tested temperature properties of the material blocks for high-sensitive temperature sensor. In this paper, four different metallic materials such as stainless steel, steel, aluminum alloy, and copper were used. We also tested temperature properties of four polymers (ABS, PC, PE, and PTFE). In case of metals, the aluminum alloy has the temperature sensitivity (dλ/dT) of 0.03862nm/℃ which is the highest value of the testing metallic materials. It is 3-fold sensitivity improvement comparing to a normal FBG temperature sensor. In addition, the temperature sensitivity of the PE polymer structure is 0.09035 nm/℃. It is improved 9 times greater than that of the normal FBG sensor. Finally, We increased the length (10cm) of PE structure and Polymide coating on the used FBG to increase its tensile strength . In this case, the temperature sensitivity was about 0.14456nm/℃. It is improved 5 times greater than 0.027nm/℃ of PE structure (1cm) and 14 times greater than the normal FBG sensor. We have confirmed that the auxiliary material structures enhanced the sensitivity of the FBG temperature sensor.