激光与光电子学进展, 2018, 55 (8): 080603, 网络出版: 2018-08-13
基于大偏置量熔接的反射式光纤型干涉仪的折射率传感特性 下载: 788次
Refractive Index Sensing Characteristics of Reflective Fiber Interferometer Based on Large Offset Splicing
光纤光学 光纤传感器 光纤干涉仪 反射式结构 偏置熔接 fiber optics fiber optic sensors fiber interferometer reflection structure offset splicing
摘要
提出并实现了一种基于大偏置量熔接的单端反射式光纤Mach-Zehnder(M-Z)干涉仪。在一段数百微米长的单模光纤两端以大偏置量对称地错位熔接两段光纤,将其中一段光纤的端面镀制薄金膜作为反射镜面,使在外界环境和光纤包层材料内传输的光产生相位差,并在器件反射端能够观测到较强的干涉光谱。实验发现,该干涉光谱随外界折射率(RI)变化可发生较高灵敏度的漂移,当偏置量为62.5 μm和空腔长度为554 μm时,测得其水环境的折射率灵敏度和空气中的温度灵敏度分别为-13257 nm/RIU(RIU为单位折射率)和37.33 pm/℃。与已报道的同类型器件相比,所提传感器具有折射率灵敏度高、结构紧凑、可单端测量以及稳定性好等优点,在生物化学传感和环境污染监控等领域中具有良好的应用前景。
Abstract
We have demonstrated a kind of single-end reflective optical fiber Mach-Zehnder (M-Z) interferometer based on large lateral-offset splicing joints. Several hundred microns of standard single-mode fiber (SMF) was spliced between two other SMFs with the same lateral offset. One fiber has its end-face coated by gold film, acting as a reflector. The beams propagating in the environmental medium and the fiber cladding material interfere and produce a phase difference. The reflected interference spectra were measured at the same side of the broadband source by an optical spectrum analyzer. The pattern of interference spectrum shifts with the change of the external refractive index (RI). The sensor with a cavity length of 554 μm and a lateral offset of 62.5 μm is demonstrated. The achieved RI sensitivity in water and the temperature coefficient in air are -13257 nm/RIU and 37.33 pm/℃, respectively. Compared with the reported counterparts, the sensor has the advantages of high refractive index sensitivity, compact structure, single-ended measurement and good stability, and has good application prospects in the fields of biochemical sensing and environmental pollution monitoring.
苏达顺, 马宽明, 孙立朋, 武创, 李杰, 关柏鸥. 基于大偏置量熔接的反射式光纤型干涉仪的折射率传感特性[J]. 激光与光电子学进展, 2018, 55(8): 080603. Su Dashun, Ma Kuanming, Sun Lipeng, Wu Chuang, Li Jie, Guan Bai′ou. Refractive Index Sensing Characteristics of Reflective Fiber Interferometer Based on Large Offset Splicing[J]. Laser & Optoelectronics Progress, 2018, 55(8): 080603.