锥形三包层石英特种光纤折射率与温度传感器

Refractive Index and Temperature Sensor of Tapered Triple Cladding Quartz Specialty Fiber

提出了一种锥形三包层石英特种光纤（TTCQSF）的折射率与温度传感器。它是通过对2根单模光纤（SMF）之间熔接的三包层石英特种光纤（TCQSF）熔融拉锥得到的SMF-TTCQSF-SMF级联结构,形成了光纤马赫-曾德尔干涉仪（MZI）。由于TTCQSF纤芯模和包层模之间的光程差会随着外界环境的变化而改变,从而引起传感器干涉谱的变化,因此可以通过检测传感光谱的变化实现对外界物理量的测量。分别对该传感器进行折射率和温度传感实验,实验结果表明,当溶液折射率在1.3350~1.3466范围、温度在25.7℃~94.9℃范围内时,随着折射率和温度的增加,传感器的传输光谱分别出现红移和蓝移现象,其折射率灵敏度和温度灵敏度分别为1673.94 nm/RIU和-0.061 nm/℃,且均具有很好的线性度,其中RIU为单位折射率。该传感器制作简单、灵敏度高,在生物化学、工业生产的折射率和温度测量场合具有较好的应用前景。

A refractive index and temperature sensor is proposed based on tapered triple cladding quartz specialty fiber（TTCQSF）. The SMF-TTCQSF-SMF structure is fabricated by drawing a section of fused TCQSF which is spliced in the both ends with two single mode fibers（SMFs）. Then an in-fiber Mach-Zehnder interferometer（MZI）is achieved. The optical path difference between the fiber core mode and cladding mode of TTCQSF can vary with the changes of the external environment. And it causes the change of the sensor interference spectrum. Monitoring the variation of the transmission spectrum can determine the ambient physical parameters. The sensing performances of refractive index and temperature of the sensor are tested, respectively. The experimental results show that the transmission spectra of the sensor have red shift when the refractive index increases in the range from1.3350 to 1.3466 and have blue shift when the temperature increases in the range from 25.7 ℃ to 94.9 ℃. The refractive index sensitivity is 1673.94 nm/RIU and the temperature sensitivity is-0.061 nm/℃, where RIU is refractive index unit. Both of them have good linearities. The sensor has the advantages of easy manufacturing and high sensitivity. So it has a good application prospect in the fields of refractive index and temperature measurement,such as biochemistry and industrial production.