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1.
光纡压力传感器探头的设计   总被引:1,自引:1,他引:0  
介绍了一种光纤压力传感器探头的设计和计算。利用平膜片实现压力与位移的转换,其位移由光纤传感器检测出来。探头中两光纤呈θ角度放置,能使系统的灵敏度达到41.6mV/MPa。传感器探头的最大承压为3mPa。  相似文献   

2.
提出一种基于氧化石墨烯(GO)微纳光纤的生物传感器,将其用于狂犬病毒(RV)的免疫检测研究。首先,将标准单模光纤通过熔接机放电形成双锥形光纤,再对双锥形光纤进行熔融拉锥制作出高灵敏度的微纳光纤。然后,在微纳光纤表面修饰GO,并将RV抗原固定于该传感器表面,用于对RV抗体的特异性检测实验。实验结果表明:该生物传感器对RV抗体的检测范围为200 fg/mL~1 ng/mL,检测极限(LOD)约为225.56 fg/mL,其检测灵敏度约为1.099 nm/log(mg·mL-1),解离系数约为2.92×10-11 M;当用于不同的抗体溶液样本和RV阳性血清的对照检测及临床检测时,该免疫传感器对前者的响应非常微弱,而对后者有明显的响应,说明其对RV抗体具有良好的特异性。基于GO修饰微纳光纤的免疫传感器具有制作简单、微纳尺寸、灵敏度高、成本低等优点。  相似文献   

3.
将单锥微纳光纤模式干涉仪和石墨烯相结合,实现了一种高灵敏度的光纤式氨气传感器,其利用石墨烯的特异性吸附效应及微纳光纤结构的高灵敏度传感特性,通过检测干涉光谱的漂移量实现了对氨气浓度微弱变化的检测.对不同组传感器进行了对比分析,结果表明当光纤直径为3.4μm时最大检测灵敏度为10.8 pm/ppm,与文献中采用其它光纤结构所报道的结果相比几乎提高了一倍.该传感器具有结构简单、易于实现及灵敏度高等优点,在危害气体浓度报警和人体健康检测等领域有潜在的应用前景.  相似文献   

4.
光纤倏逝波生物传感器探针新的几何设计   总被引:1,自引:0,他引:1  
为提高光纤倏逝波生物传感器的探测效率和灵敏度,根据光纤的模式匹配理论计算了给定条件下光纤探头的模式匹配半径,以此匹配半径为基础分析激发光在线性锥型光纤探头中的光线传输轨迹.结合倏逝波透射深度与光线入射角之间的关系,提出一种新的抛物线锥形光纤探头.计算结果表明,为使入射光在均匀感应部分激发的能量最大,入射角在锥形感应部分必须满足在锥形终端最小且刚好是临界角的条件.通过修正抛物线锥形参数,使入射角在满足全反射条件下更加接近于临界角,从而获得比线性锥形更深的透射深度.灵敏度测试实验结果表明抛物线锥形的灵敏度比其它探针测试效果好,说明凹形抛物线锥形探针能够与待测的生物样品之间构成一种理想的荧光收集与激发机制,实验与理论结果比较吻合.  相似文献   

5.
基于折射率调制原理的光纤生物传感器的研制   总被引:1,自引:0,他引:1  
吴鹏  秦水介 《激光与红外》2011,41(9):1006-1009
根据光纤内光强损耗与芯外的环境有效折射率之间的关系,设计了一种结构简单、易于操作、成本低廉、灵敏度较高的折射率调制型的光纤生物传感器.文中对该传感器的结构进行了理论分析,通过对不同浓度葡萄糖溶液的检测,研究了该传感器的传感特性.结果表明:该传感器的检测灵敏度可以达到μmol/L量级,并具有较好的线性特性.  相似文献   

6.
基于气体的近红外吸收机理,研究了一种可以检测多种气体的光纤传感器.根据被测气体的吸收峰对应波长选择不同的分布反馈式半导体激光器为光源.采用光纤多通道同时测量,配以独特设计的气室探头,可用于煤矿等恶劣环境.对甲烷和一氧化碳气体浓度的检测实验表明,该系统具有较高的灵敏度、精度、稳定性.  相似文献   

7.
全保偏光纤加速度矢量传感器的设计与实验   总被引:2,自引:0,他引:2  
阐述了全保偏光纤加速度矢量传感器的基本工作原理,进行了三维探头结构设计,对系统的谐振频率和加速度灵敏度进行了理论分析,并进行了一维光纤加速度传感器实验,验证了这种全保偏光纤加速度矢量传感器的谐振频率和加速度灵敏度理论分析和结构设计的合理性.  相似文献   

8.
一种用于复合材料固化监测的传感器的研究   总被引:1,自引:0,他引:1  
光纤表面等离子体波传感器具有结构简单、灵敏度高等特点,它不仅具有理论上的研究价值,而且在工程中的应用前景也十分广阔。运用光纤表面等离子体波来测量折射率是一种简便、灵敏的方法,可以利用这一特性制作出通过检测折射率对复合材料进行固化检测的光纤表面等离子体波传感器。本文研究了利用光纤表面等离子体波传感器对不同折射率的溶液进行测试的方法。设计了一种用于折射测试的光纤传感探头,它性能可靠,使用方便。研制了溶  相似文献   

9.
基于简单的蘸取技术和紫外光固化技术集成锥形聚合物波导结构与光纤制备了一种高灵敏光纤温度传感探头.实验结果表明,该结构在低温时的温度灵敏度为123.6 pm/℃,且其灵敏度随温度的升高呈非线性增加趋势.其中,聚合物波导的结构紧凑,轴向尺寸为300 μm,径向最小尺寸为2μm.基于该波导制备的探头具有较好的温度响应特性、生物兼容性且能实现点探测,在生物医疗等领域有着重要的应用前景.  相似文献   

10.
基于光声光谱法的光纤气体传感器研究   总被引:5,自引:0,他引:5  
论述了光声光谱信号的产生。提出用光纤相位传感器代替传统的微音器检测光声信号 ,讨论了光纤中光波的相位变化与光声信号的关系。设计了光学长程结构 ,有效增加了对光功率的吸收。用染料激光器作光源对SO2气体浓度进行测量。实验表明 ,最低检测灵敏度可达 1 2× 10 -10 。由于采用光谱技术与光纤技术相结合 ,使研制的传感器具有较高的灵敏度 ,信号的传输通道具有强的抗电磁干扰及防燃防爆能力。气体探头体积小 ,响应速度较快。信号处理电路具有较强的抑制噪声干扰能力。该传感器及其系统在灵敏度、精度、响应时间等性能指标上达到了检测气体含量要求  相似文献   

11.
A fiber-optic biosensor capable of remote continuous monitoring has recently been designed. To permit sensing at locations separate from the optoelectronic instrumentation, long optical fibers are utilized. An evanescent wave immune-probe is prepared by removing the cladding near the distal end of the fiber and covalently attaching antibodies to the core. Probes with a radius unaltered from that of the original core inefficiently returned the signal produced upon binding the fluorescent-labelled antigen. To elucidate the limiting factors in signal acquisition, a series of fibers with increasingly reduced probe core radius was examined. The results were consistent with the V-number mismatch, the difference in mode carrying capacity between the clad and unclad fiber, being a critical factor in limiting signal coupling from the fiber probe. However, it was also delineated that conditions which conserve excitation power, such that power In the evanescent wave is optimized, must also be met to obtain a maximal signal. The threshold sensitivity for the optimal step-etched fiber probe was improved by over 20-fold in an immunoassay, although, it was demonstrated that signal acquisition decreased along the probe length, suggesting that a sensor region of uniform radius is not ideal  相似文献   

12.
为了研究微纳光纤的导波和远场辐射特性,采用模式理论和衍射理论分析了微纳光纤芯径与模场、z向能流密度、有效模面积和远场强度的关系,并通过拉锥光纤进行了实验验证。结果表明,通过合理设计,微纳光纤的大部分能量在包层中以倏逝波的形式传输,光纤的有效模面积可以超过1000μm2。拉锥光纤的实验证实了微纳光纤可以有效地传输导波并把其辐射出去。  相似文献   

13.
Sharp optical fiber tips for photon scanning tunneling microscopes (PSTMs) have been fabricated by employing a new alternative technique for etching multimode optical fibers. The tip diameter is less than 30 mm, while the cone full-angle can be as sharp as 3°. To the knowledge of the authors, such tips are the sharpest reported up to now. Measurements, with 19 tips, of the evanescent wave decay distance produced by frustrated reflection of light on a same sample, show good reproducibility. Furthermore, the PSTM images, taken with the new tips, are very sharp and fit with images of the same sample obtained with an atomic force microscope (AFM)  相似文献   

14.
For pt.I see ibid., vol.41, no.6, p.578-84 (1994). A biosensor was developed using antibodies, fluorescence and the evanescent wave to detect antigen binding at the surface of an optical fiber. Cladding was removed from the core along the distal end of a step-index optical fiber, and recognition antibodies were immobilized on the declad core to form the probe sensing region. Immersing the declad probe in aqueous solution creates a V-number mismatch between the immersed probe and the clad fiber. Probes created with reduced sensing region radius exhibited improved response by decreasing the V-number mismatch. Tapering the radius of this region has further improved probe response. Ray tracing analysis of the tapered probe demonstrated that the evanescent wave penetration depth increases along the length of the taper. Experiments correlating position of refraction along the taper with launch angle at the proximal end were realized in the ray tracing model. An evanescent wave immunoassay was performed with a series of the tapered fiber probes, each tapered from the fiber core radius (100 μm) to different end radii. An end radius of 29 μm was found to produce maximal signal from the tapered probe. Factors leading to the determination of the optimized probe are discussed  相似文献   

15.
介绍了基于倏逝波激发的荧光免疫型光纤生物传感器的基本原理,针对其中应用的各种方法进行了分析。基于倏逝波激发的荧光免疫型光纤生物传感器的免疫检测方法、探头发展和系统结构发展.对国内外的最新产品和技术及其应用情况进行了介绍和概述,并结合新技术的出现和系统整体结构的演变趋势对免疫型倏逝波光纤生物传感器的发展进行了展望。  相似文献   

16.
基于光纤倏逝波传感器的磷酸根离子检测   总被引:2,自引:2,他引:0  
提出了利用光纤倏逝波传感器通过光吸收方法来测量溶液中磷酸根离子浓度的新方法。将通信用标准单模光纤(SMF)局部腐蚀到接近芯层后放入不同浓度的磷钼蓝溶液中,当以磷钼蓝光吸收峰值为探测光波长时,光纤表面的倏逝波会部分被溶液吸收,通过测量光纤输出光强来计算溶液中的磷酸根离子浓度。实验结果表明,磷钼蓝溶液中磷浓度为0.04~O...  相似文献   

17.
耦合型微纳光纤偏振滤光器研究   总被引:2,自引:0,他引:2  
杜垚  陈哲  余健辉  翟艳芳  张军  陈春艳  李浩智 《中国激光》2012,39(6):610002-216
微纳光纤偏振滤光器是光纤通信和传感系统的微型基本元件之一。利用超模耦合理论研究表明,当选择合适的耦合区长度和微纳光纤直径时,两平行紧贴微纳光纤构成的耦合器件可实现起偏效应,即将非偏振的输入光变为偏振光输出;理论设计分析给出了产生这种效应的几何参量值。实验研究了两根微纳光纤平行耦合时输出光偏振度(DOP)与耦合长度的关系,验证了起偏效应并制作了基于消逝场耦合的微纳光纤偏振滤光器。实验表明当微纳光纤偏振滤光器输入非偏振光时,在1545~1560nm波段耦合输出端光的偏振度达到了90%以上,实现了光束起偏;在此波段内某些波长的输出光消光比(LPER)可达到24dB以上,而其他波长处为椭圆偏振光或者圆偏振光,实现了分色起偏。此器件与检偏器组合可制成带通(阻)波长滤波器。  相似文献   

18.
A new and simple method of pumping short high-power optical fiber lasers and amplifiers is described. In our approach, several passive coreless optical fibers are brought into direct contact alongside a single rare-earth doped active fiber which constitutes the active medium of the laser (amplifier). Pump light is delivered through the passive coreless fibers and penetrates into the active fiber via evanescent field coupling. To enhance the pump absorption in the gain medium, high-order spatial modes are excited in the pump delivery fibers, and an active fiber with high concentration of the dopant ions is used. As a demonstration of the viability of our approach, test results are reported on a 12-cm-long Er/sup +3/-Yb/sup +3/ codoped phosphate glass fiber laser. The laser output reaches 5 W using 23-W pumping into six coreless fibers. Above threshold, the laser has /spl sim/24% optical-to-optical conversion efficiency (with /spl sim/64% being the theoretical maximum). The linearity of the input-output characteristic for the laser suggests that the output power can be scaled up by applying higher pump power.  相似文献   

19.
Infrared silver halide fibers were studied concerning the optical degradation induced by photodarkening. Infrared transmittance decreased notably in the shorter wavelength (near-infrared) region by the exposure to ultraviolet (UV) or visible light below a wavelength of ~600 nm. Black paint was tentatively coated on the unclad fiber for photodarkening protection, but the infrared transmittance of the fiber decreased heavily due to the evanescent wave absorption by the paint. To reduce this absorption loss, a fluorocarbon polymer was coated between the fiber core and the black paint. Consequently, efficient transmission was realized in the infrared region except for the 7-10-μm wavelength range, where the fluorocarbon polymer has a strong absorption band. In the 2-7-μm wavelength range, the fiber that was heated at 100°C in the polymer coating process exhibited higher transmittance than the original uncoated fiber. No optical degradation of the coated fiber was observed, even after irradiation with UV light for a period of 70 h  相似文献   

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