集成光路－光纤传感器及其进展

多功能集成光路技术与光纤传感器相结合，代表了光纤传感技术的一个重要发展方向。本文介绍集成光路在光纤陀螺、电场传感器、压力传感器和振动传感器等方面的应用及其进展。     

Real-time measurement of multipoint hetero-core fiber optic binary sensors based on optical pulse loss change

Hetero-core fiber optic sensors can transmit sensing and communication signals on a single fiber optic transmission line and have numerous advantages for environmental information monitoring such as home security. Moreover, these sensors are cost effective due to their temperature independence and light-intensity-based measurements. We have previously developed a hetero-core fiber optic binary sensor that can be connected in series to detect the number of doors and windows that are opened or closed. In this paper, we propose an improved method for using hetero-core fiber optic binary sensors that are connected in series, which are referred to as binary switches. A unique pulse loss change enables the states of the connected switches to be identified. As a result, the total optical loss in the transmission line is reduced. Therefore, the number of binary switches connected in series can be increased on a single transmission line. The unique pulse loss peaks can be controlled by the action of a flat spring and by adjusting the position of the flat spring inside the binary switch module. Typical pulse peaks of each binary switch are from 0.13 to 0.75 dB in the positive direction and from −0.47 to −0.03 dB in the negative direction, while the typical insertion loss is from 2.23 to 2.61 dB, depending on the position of the hetero-core segment within the binary switch module. The connection of two binary switches in series is successfully demonstrated for monitoring the optical loss change on a single transmission line. The results of the present study show that the number of binary switches connected in series can be increased significantly on a single transmission line.     

集成光路－光纤传感器及其进展

多功能集成光路技术与光纤传感器相结合，代表了光纤传感技术的一个重要发展方向。本文介绍集成光路在光纤陀螺、电场传感器、压力传感器和振动传感器等方面的应用及其进展。     

Fiber optic humidity sensors for high-energy physics applications at CERN

This work is devoted to a feasibility analysis for the development of novel fiber optic humidity sensors to be applied in high-energy physics (HEP) applications and in particular in experiments actually running at the European Organization for Nuclear Research (CERN). On this line of argument and due to the wide investigations carried out in the last years aimed to assess the radiation hardness capability of fiber optic technology in high energy physics environments, our multidisciplinary research group has been recently engaged in the development of near-field fiber optic sensors based on particle layers of tin dioxide to perform the monitoring of low values of relative humidity RH even at low temperatures.While this sensor type has been successfully employed for ppm and sub-ppm chemical detection in air and water environments, it is the first reported use for relative humidity measurements.The RH sensing performance of fabricated probes was analyzed during a deep experimental campaign carried out in the laboratories of CERN, in Genève. A very good agreement was observed between humidity measurements provided by the optical fiber sensors and commercial polymer-based hygrometers at 20 °C and 0 °C, with limits of detection for low RH regimes below 0.1%.     

光纤高温传感器表面镀膜技术研究

在高温测试中,光纤高温传感器具有独特的优势,在制作光纤高温传感器过程中,镀膜技术是一个关键的环节。根据高温测试需要,选取了合适的镀膜材料,对氧化锌（ZnO）和氧化镁铝（MgAl2O4）的物理化学性质进行了介绍,同时根据材料特性选择了适合的镀膜方法,分别适用于黑体腔温度传感器的头部镀层和光纤光栅传感器表面镀膜,取得了良好的效果,达到了温度测量的要求。     

Mathematical models for assessment of the safety of steel beams based on average strains from long gage optic sensors

Most fiber optic sensors are point sensors that can measure the strain only at a local point of a beam, although strain distribution is non-uniform along the length of a beam. Long gage fiber optic sensors that measure integrated strain over a relatively long length can consider strain variation. This type of sensor was found to be efficient and useful for monitoring large-scale structures. On the other hand, the maximum strain in a beam cannot be measured with long gage optic sensors; the safety of a steel beam is analyzed by a comparison between the maximum stress measured during monitoring and the allowable stress of the beam calculated by a design code. Therefore, in this paper, simple mathematical models are presented for the determination of the maximum values of strains or stresses in a beam based on the average strains measured by long gage optic sensors. The model was tested in an experiment by comparing the maximum strain directly obtained from electrical gages and the calculated maximum strain from long gage optic sensors.     

Fiber optic sensors for wearable applications

This paper focuses on studying different fiber optic sensors and their suitability for wearable applications. The properties of fiber optic sensors are compared against the requirements of wearability. The properties of optical fibers and textile fibers are also compared and integration methods reviewed. The aim of the work is to define which fiber optic sensors could be used in wearable applications and in clothing and which not, at the moment and in the future. It is found out that mechanical properties of the fibers are the most significant from the integration point of view, and optical fibers are compatible with the textile fibers with certain restrictions. Four out of 16 different fiber optic sensors are evaluated to become suitable for wearable applications at the moment, while few sensors have potential to become suitable for wearable applications in the future. Two of the suitable sensors were further tested by creating alternative structures and testing their behavior. One structure was then chosen, for an example wearable application design. This evaluation and demonstration creates a good foundation for further research in the field of wearable fiber optics.     

A miniaturized pH and pCO2 intravascular catheter using optical monitoring and a dual concentric-flow microdialysis approach

Hollow fiber membranes are found to allow the development of extremely small diameter (0.22 mm) probe and catheter-type pH and pCO₂ sensors. These types of sensors can be comparable to the size of fiber optic sensors for these analytes. This work employs a concentric-flow geometry to direct a micro-flow of sweep solutions through hollow fiber membranes made of cuprammonium rayon and silicone. The sweep solutions establish a diffusive equilibrium with the external environment and then flow into optical absorbance cells. The optical system, which is remote from the sensor membranes, consists of two separate transparent capillaries, 555-nm surface-mount LEDs and photodetectors to monitor absorbance changes. In buffer, a ±0.01 pH unit resolution is achieved over the range of 7.02–7.87 with a 5-min 90% response time, and a 1.5-mm Hg pCO₂ resolution is achieved from 0 to 80 mm Hg with a 15-min 90% response time.     

Optical fiber pH sensor based on lossy-mode resonances by means of thin polymeric coatings

This work describes the fabrication of an optical fiber sensor with spectral response to pH based on the deposition of a thin polymeric coating on an optical fiber core. If the thin polymeric coating has a high refractive index real part and a non-null imaginary part, this permits a coupling of light to the modes guided in the polymeric coating originating optical resonances. These resonances are named by some authors as lossy-mode resonances (LMR) or guided-mode resonances. Moreover, the location of the resonances in the optical spectrum varies as a function of the coating thickness and refractive index. Hence, the utilization of the well-known poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) pH sensitive polymeric coating that presents a variation of the thickness with the pH of the solution (known as swelling/deswelling behaviour) permits the fabrication of optical fiber pH sensors based on wavelength detection. The fabrication of ready-to-use devices requires considering several aspects such as the adequate polymeric coating thickness or the selection of the resonance to be monitored. As a result, LMR-based optical fiber pH sensors with accuracy of ±0.001 pH units and an average sensitivity of 0.027 pH units/nm within the range between pH 3 and pH 6 have been obtained after an adequate design.     

光纤麦克风传感探头的设计研究

提出了一种新型反射式光纤麦克风的理论设计,首次采用了Y形单根多模反射式光纤传感探头结构的形式,并在对光纤传感探头的理论研究基础上建立数学模型,给出了接收光纤接收光强的计算公式以及光强调制的理论曲线.另外,从理论和实验两个方面设计了实验型光纤麦克风并给出系统设计的整体结构框图.     

光纤传感器及其在物业管理中应用

随着科技的发展,物业管理更趋于网络化、智能化,而传感器则是所有信息的来源,因此传感器在物业管理中发挥者越来越大的作用.由于光纤技术的不断发展,传输距离不断加大,价格下降,加上在技术性能上又有独到的优点,光纤传感器将在物业管理中越来越多地得到应用.本文介绍了光纤传感器及其在住宅物业安全管理中的应用的设计思想,并提出组成光纤传感器网络,利用神经网络技术对信号进行实时处理,达到实时监控的目的.     

光纤微弯传感器技术的发展与应用研究

光纤微弯传感器是一种强度调制型光纤传感器,通过光纤微弯曲导致传输光强度的损耗变化,来测量压力、温度、加速度、应变、流量、速度等环境参量;介绍了光纤微弯传感器的工作原理和特点,并详细论述了国内外光纤微弯传感器技术的发展与应用,最后,分析了光纤微弯传感器存在的局限性。     

Fiber optic glucose sensor based on bionanofilms

In this paper a glucose fiber optic biosensor based on electrostatic self-assembly adsorption technique is proposed. Up to 35 bilayers biofilm was achieved from alternate deposition of enzyme glucose dehydrogenase and polyelectrolytes polyethyleneimine and poly(sodium 4-styrenesulfonate). The layer thickness was characterized using an in situ optical near infrared interferometry method, which showed formation of nanoscale multilayer structure as a function of alternate adsorption cycles. Experiments showed highly efficient adsorption. The catalytic effect of the multilayer film on the reduction of nicotinamide adenine dinucleotide was studied utilizing ultraviolet fiber optic spectroscopy. The performance of this nanobiofilm onto both the cleaved end of an optical fiber pigtail and a tapered optical fiber structure were compared. As a result enzymes kept their activities after immobilization; the biosensor showed high sensitivity and stability during storage.     

光纤表面等离子体波传感器中共振波长的理论计算

光纤SPR传感器是一种新型传感器,可在多个领域实现远距离实时在线监测.根据表面等离子体波的共振条件计算了光纤SPR传感器的关键参数--共振波长,并且给出在一定条件下传感器的最大量程.为光纤SPR传感器的设计提供了有力的工具.     

光纤传感器在灵巧结构与蒙皮中的应用

介绍了光纤传感器在飞行器结构上的应用，包括表面贴装与内埋光纤损伤探测系统，内埋的监测复合材料内部声波辐射的光纤应变传感器及测量复合材料的内应变张量的应变计，并介绍了光纤神经网络的初步研究。     

The application of a light guiding flexible tubular waveguide in evanescent wave absorption optical sensing

A light guiding flexible fused silica (FFS) capillary has been used in designing evanescent wave (EW) absorption based chemical sensors. The FFS capillary is similar to a conventional silica optical fiber in that it can guide light in the wavelength region from UV to near infrared, but different from a conventional optical fiber in that it is a tubular waveguide. The inner surface of the FFS capillary is fused silica, which was coated with a reagent doped polymer in order to design an optical fiber chemical sensor. The FFS capillary has a cladding layer plus a protection polymer coating on its outside surface. The cladding layer ensured the capability of the FFS capillary for guiding light. The protection coating increases the FFS capillary's mechanical strength and makes it robust in practical applications. This makes the FFS capillary very useful in designing an EW based optical chemical sensor of a long path length. Techniques for activating the inner surface of an FFS capillary, coating the inner surface of the capillary with a polymer, connecting the coated capillary to a light source and a photodetector, and delivering a sample through the capillary have been developed in this work. Three optical sensors for sensing Cu(II), toluene in water samples and ammonia in a gas sample have been fabricated and tested. Preliminary test results obtained in this work illustrate the feasibility of fabricating highly sensitive EW absorption based chemical sensors with the light guiding FFS capillary.     

Effect of fiber core dopant concentration on the performance of surface plasmon resonance-based fiber optic sensor

In the present work we study the influence of varying concentrations of different fiber core dopants on the sensor performance in terms of sensitivity, signal to noise ratio (SNR) and operating range of surface plasmon resonance (SPR)-based fiber optic sensors. We consider the use of different concentrations of GeO₂, B₂O₃ and mixture of both in the core of plastic cladded silica (PCS) optical fiber. The study is further extended to consider the performance of quenched fiber. We show how sensitivity and signal to noise ratio of surface-plasmon-based fiber optic sensors can be optimized by wisely choosing their fiber core doping.     

强度调制型光纤网络温度传感器多路检测技术

本文结合时分复用形式的网络用频率域的方法处理 ,设计了一个具有两个强度调制型传感器的系统 ,并对实际光纤网络温度传感器系统响应进行了测量和数据处理 ,并又分析和计算出强度受调制的两路光的通光率 ,从而完成了对温度的测量     

基于光谱检测的光纤温度传感器

一种应用波长原理的光纤测温新技术 ,这种波长技术是基于某些半导体 (如GaAs)的光学吸收限产生的频移 ,半导体小棱镜粘在远离光纤测头的一端 ,并用一个快速扫描分光计来检测靠近探头处宽带光源的吸收频移 ,这种分光计由衍射光栅和阵列式硅光电探测器组成。系统的测温范围在 2 0℃至 175℃     

面向人体健康防护的光纤生化传感技术

光纤生化传感器因具有不受电磁干扰、绝缘性好、安全防爆、损耗低和耐腐蚀等优点,在人体健康防护领 域表现出了良好的应用价值:及时且有效地监测污染物可为环境污染物的有效控制提供数据支撑,从源头上减少疾病的发生;准确且灵敏地检测疾病标志物可诊断人体疾病的情况,从而使得疾病的预防和早期治疗成为可能.对应用于人体健康防护中的光纤生化传感器进行全方位地概述:首先,介绍其使用的光纤传感原理;然后,总结并分析应用于气体和水质污染物监测的光纤生化传感技术;接着,总结并分析应用于人体呼出气体和生物体液检测的光纤生化传感技术;最后,讨论光纤生化传感器在人体健康防护领域实际应用的一些限制因素以及未来的发展方向.