A temperature sensor based on the splicing of a core offset multi-mode fiber with two single mode fibers

In this paper, a temperature sensor based on the splicing of a core offset multi-mode fiber with two single mode fibers is proposed and demonstrated experimentally. The temperature sensing principle is analyzed and related experiment is performed. By controlling the core offset and splicing length of the specialty multi-mode fiber (SMMF), two sensors with different temperature sensing properties are obtained, and experimental results show that the temperature sensitivity can be up to 48.76 pm/°C in the range of 25—95 °C. Moreover, it has many advantages, including small size, high sensitivity, and simple structure. So it can be used in potential temperature sensing applications, such as industrial production, biomedical science, power electronics, and so on.     

Miniature Fabry-Perot interferometric sensor for temperature measurement based on photonic crystal fiber

A novel miniature Fabry-Perot interferometric (FPI) temperature sensor is proposed and demonstrated experimentally. The modal interferometer is fabricated by just splicing a section of photonic crystal fiber (PCF) with a single-mode fiber (SMF). The air holes of the PCF are fully collapsed by the discharge arc during the splicing procedure to enhance the reflection coefficient of the splicing point. The transmission spectra with different temperatures are measured, and the experimental results show that the linear response of 11.12 pm/°C in the range of 30–80 °C is obtained. This sensor has potential applications in temperature measurement field.     

待熔光子晶体光纤中的热传导特性

在光子晶体光纤(PCF)的熔接过程中,由于包层空气孔结构的存在,同在熔接过程中存在着潜在的空气孔形变,使得加热过程更为复杂.对待熔的光子晶体光纤的热传导特性进行了研究,以二氧化碳激光作为熔接热源,根据传热学及能量守恒定律建立三维对称的热传导模型,进而对光子晶体光纤熔接的瞬态传热过程进行仿真分析和实验研究.分析表明,该模型可以很好地确定影响光子晶体光纤熔接过程中热传导特性的各个主要因素,为最终确定最佳熔接条件建立理论基础.     

A tension insensitive PbS fiber temperature sensor based on Sagnac interferometer

In this paper, a tension insensitive PbS fiber temperature sensor based on Sagnac interferometer is proposed and demonstrated. The sensing mechanism of tension and temperature is analyzed. The relationships between the interference spectrum, temperature and tension are analyzed, respectively. The experimental temperature range is 36—70 °C. The experimental results show that the interference spectrum is red shifted, and its sensitivity is 53.89 pm/°C. In tension experiment, the tension range is 0—1 400 με. The experimental results show that there is no wavelength shift in the interference spectrum. The sensor is immune to tension cross-sensitivity compared with other sensors. It can be used for temperature testing in aerospace, chemistry and pharmacy.     

光子晶体光纤熔接损耗研究

基于有限元法分析了光子晶体光纤模场半径,为了提高计算速度,提出了一种工作波长为1．55μm时,光子晶体光纤模场半径的快速估算方法,进而实现光子晶体光纤熔接损耗的快速估算。分析表明,本文提出的方法能够准确快速的实现光子晶体光纤熔接损耗的估算。     

Refractive index insensitive temperature sensor based on waist-enlarged few mode fiber bitapers

A refractive index insensitive temperature sensor based on waist-enlarged few mode fiber (FMF) bitapers is presented. The first section of FMF is spliced between two single-mode fibers. In fusion process, the waist-enlarged FMF bitapers can be obtained by large current discharging repeatedly. The refractive index and temperature sensing mechanisms are analyzed. For the sensors with different sizes, the refractive index and temperature experiments have been performed. The results show that in the refractive index ranges of 1.335 0—1.346 6 and 1.348 2—1.419 3, the refractive index insensitivity is verified. In a temperature range of 31.9—90 °C, the sensor sensitivity can be up to 85.57 pm/°C. In addition, it has a compact structure. Therefore, the sensor can avoid the cross sensitivity for measuring the refractive index and temperature simultaneously.     

基于长周期光纤光栅的成品油中乙醇含量检测

提出采用长周期光纤光栅(LPFG)测量乙醇汽油与乙 醇柴油的研究。利用耦合模理论分析了LPFG的折射率敏感特性,得到LPFG谐振波 长漂移量与外界环境折射率的关系,并将其用于乙醇汽油 和乙醇柴油中乙醇含量的检测,得到乙醇汽油与乙醇柴油中乙醇含量与LPFG谐振波长漂移量 的 关系。实验结果表明,乙醇汽油中,乙醇含量每改变1%,谐振波长平均漂移量为0. 047nm;而乙醇柴油溶 液中,乙醇含量每改变1%,谐振波长平均漂移量为1.154nm。实验测量与 理论仿真的结果基本一致,验证了LPFG用于乙醇汽油和乙醇柴油检测的可行 性。     

Analysis of the enhanced coupling efficiency for different profile curves of special optical taper

For enhancing the coupling efficiency between the beam and the photodiode, a special optical taper is proposed for receiving optical signal. Based on the circular symmetric structure of special optical taper, the profile curve equations of it are deduced, including the trigonometric function type, parabolic type and exponential type. Moreover, the coupling efficiencies for special optical tapers with different profile curves are studied. The relationships of incident position, incident angle and coupling efficiency are analyzed. Finally, the comparison of coupling efficiency analytical results is also given.     

40倍长工作距离PCF熔接系统显微物镜设计

针对PCF熔接系统对显微物镜的长工作距离、高放大倍率和高分辨力的需要,本文设计了一组用于光子晶体光纤端面成像的特殊物镜,并通过ZEMAX仿真优化。该物镜具有40?高放大倍率、5mm长工作距离、1μm的高分辨力、500μm×500μm较大视场等特点。通过实验验证该物镜达到了设计要求。     

镀膜玻璃在线质量检测系统的研究和实现

基于光学的色散原理,本文研制了一种可以在线检测镀膜玻璃光学性质的仪器。该仪器采用光纤作为传光载体,利用线阵CCD与光栅的配合完成对玻璃透射和反射光谱测量。光纤对光的发射和接收避免了杂散光的干扰噪声;光栅和高灵敏度的线阵CCD可实现高精确度的光谱采集。通过计算机强大的计算能力,可以实现透射率、反射率、各种色差测量和显示,如CIE1931色坐标（x,y）以及CIE1976色坐标（U,V,W）等,并且能够反馈给生产线,实现对镀膜玻璃光学特性的在线检测及生产线的自动控制。