中文摘要：

研制了一种通过手工熔接方法在两段单模光纤（SMF）间焊接一段实芯光子晶体光纤（PCF）而形成的Mach-Zehnder干涉仪（MZI）传感器,研究了传感器传输光谱与外界折射率的关系。实验结果表明,这种MZI传感器的中心波长随着外界折射率的增加向长波方向漂移,在1.340-1.384的折射率变化范围内,干涉长为3.2cm的MZI传感器灵敏度为70.45 nm/RIU。通过腐蚀可以进一步提高传感器干涉光场与外界折射率的耦合程度,腐蚀后传感器的折射率灵敏度可提高到198.77 nm/RIU,约为腐蚀前的2.8倍。在30~100℃温度范围内,传感器的温度灵敏度仅为0.0019 nm/℃,因此在应用中可以克服温度交叉敏感问题,从而为生物化学领域的测量提供了一种全光纤型器件。

英文摘要：

This paper presents a fiber-optic refractive index sensor based on the Mach-Zehnder interferometer（MZI） formed by splicing a section of endless singlemode photonic crystal fiber between two sections of conventional single-mode fibers.The relationship between the resonance wavelength shift and the refractive index is investigated.Experimental results show that the resonance wavelength shifts to the longer wavelength with the increase of the refractive index,and the sensitivity is 70.45 nm/RIU for a MZI with interference length of 3.2 cm as the refractive index ranges from 1.34 to 1.384.To enhance the coupling coefficient between the interference field and the refractive index,the interference beam of the MZI was etched.The refractive index sensitivity has been increased up to 198.77 nm/RIU after being etched,which is 2.8 times of the aforementioned MZI.In addition,such a sensor is insensitive to temperature with a sensitivity of 0.001 9 nm/℃ as the temperature ranges from 30 ℃ to 100 ℃.Therefore,such a MZI can overcome the temperature cross-sensitivity when it is used for the refractive index measurement,which offers an alternative device in chemical and biology fields.