共查询到16条相似文献,搜索用时 62 毫秒
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单模光纤渐逝波传输分析 总被引:10,自引:3,他引:7
基于光波导理论,分析了单模光纤的渐逝波传输特性,在光纤包层介质具有吸收特性的情况下,导出了渐逝波传输的透入深度公式,得出了单模光纤在轴向上的功率传输情况;讨论了在不同的折射率或消光系数下,渐逝波的透入深度和功率损耗变化特性。研究结果可用来实现高精度、高灵敏茺的单模渐逝波传感器,并应用于医学诊断,环境检测,生物和化学分析等方面。 相似文献
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普通单模光纤中光孤子传输问题的研究 总被引:1,自引:0,他引:1
在使用普通单模光纤的光孤子传输系统中,放大器自发辐射(ASE)噪声和色散波逸出是限制光孤子传输的两个主要因素,它们将引起孤子能量科动和定时抖动,从而导致系统误码。本文分别研究了带限光滤波器对ASE噪声的抑制和非线性增益对色散波的抑制以及对孤子传输系统的稳定作用,并设计了使用普通单模光纤的光孤子传输系统。 相似文献
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基于倾斜光纤Bragg光栅的横向压力传感器研究 总被引:1,自引:2,他引:1
设计了一种基于4°倾斜光纤Bragg光栅(TFBG)和弹 性 材料的横向压力传感器。利用TFBG光谱对周围介质折射率响应的特性,实现了 对较低压力范围(0~7N)的线性测量。采 用快速傅里叶变换(FFT)方法对光谱进行解调,测量灵敏度可达1920 a.u./(N/mm),线性拟 合度为0.998。研究了不同弹性材料对测量灵敏度的影响,实现对测 量范围和测量灵 敏度的调谐。本文传感器工作在反射光谱方式,易于集成(光栅区长度仅5mm),可以植入弹 性材料内部用于协调接触压力的测量。 相似文献
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黄虎清 《南京邮电学院学报(自然科学版)》1996,16(2):44-47
根据麦克斯韦方程,使用普通数学方法推导出弱导波单模非线性光纤中子光孤子的传输方程,进而解出了光弧子波的表达式。所得结果与其它献一致。 相似文献
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LIUZhiyan WANGYutian 《半导体光子学与技术》1996,2(1):18-24
An optically powered sensor for measuring pressure which is linked by optical fiber is developed in new scheme.Its pulse positio modulation(PPM)optical signal and op-tical supply power for electronics in probe are transmitted via a single optical fiber.The opti-cal power is carried by a 1300nm laser diode(LD)and the sensing data are carried by a 850nm LED.The remote ptobe uses all CMOS chips and particular modulations(PPM and PWM).Its electrical consumption including signal manipulation and LED driven current from optically converted is less than 100μW.The laser diode supplies 5mW optical power into fhe fiber.A Photodetector converts suffichently this power into electrical power to drive the whole probe operation.The optically powered distance gets up to 500m.The novel sen-sor combines optical fiber and electronies technology into a system.Because of using the prin-ciple of ratio measurement between measured and reference signals.as well as light feedback,the system is available with high reliab,outstanding accuracy and repeatability. 相似文献
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LIUZhiyan 《半导体光子学与技术》1996,2(2):137-141
In this paper an optically-powered optical fiber sensor for pressure mea-surement is introduced.Differential strain gauges of diffused silicon are emploped as sensing elements and a micro-consumption circuit is used in the probe.Pulse width modulation and pulse position modulation are adopted for signal processing. 相似文献
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Zhuo Liu Ye Ma Han Ouyang Bojing Shi Ning Li Dongjie Jiang Feng Xie Dan Qu Yang Zou Yue Huang Hu Li Chaochao Zhao Puchuan Tan Min Yu Yubo Fan Hao Zhang Zhong Lin Wang Zhou Li 《Advanced functional materials》2019,29(3)
Changes in endocardial pressure (EP) have important clinical significance for heart failure patients with impaired cardiac function. As a vital parameter for evaluating cardiac function, EP is commonly monitored by invasive and expensive cardiac catheterization, which is not feasible for long‐term and continuous data collection. In this work, a miniaturized, flexible, and self‐powered endocardial pressure sensor (SEPS) based on triboelectric nanogenerator (TENG), which is integrated with a surgical catheter for minimally invasive implantation, is reported. In a porcine model, SEPS is implanted into the left ventricle and the left atrium. The SEPS has a good response both in low‐ and high‐pressure environments. The SEPS achieves the ultrasensitivity, real‐time monitoring, and mechanical stability in vivo. An excellent linearity (R 2 = 0.997) with a sensitivity of 1.195 mV mmHg?1 is obtained. Furthermore, cardiac arrhythmias such as ventricular fibrillation and ventricular premature contraction can also be detected by SEPS. The device may promote the development of miniature implantable medical sensors for monitoring and diagnosis of cardiovascular diseases. 相似文献
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Shaobo Gong Jinxi Zhang Chenchen Wang Kailiang Ren Zhong Lin Wang 《Advanced functional materials》2019,29(41)
This study reports a self‐powered pressure sensor based on a monocharged electret nanogenerator (MENG). The sensor exhibits great advantages in terms of high reliability, ease of fabrication, and relatively high sensitivity. The working mechanism of the MENG sensor is studied by both theoretical derivations and finite element analyses to determine the electric potential distribution during the device operation. The MENG sensor exhibits a stable open circuit voltage ≈10 V at a 30.8 kPa pressure and a corresponding sensitivity of 325 mV kPa?1. The stability testing result shows that the device has only ≈5% attenuation after 10 000 cycles of repeated testing at 30.8 kPa pressure. Furthermore, it is found that the MENG sensor responds not only to a dynamic force but also a static force. Finally, a sensor array consisting of nine MENG sensor elements is fabricated. The testing results from the sensor array also reveal that a single touch of the sensor element can immediately light up an LED light at the corresponding position. This device holds great promise for use in future tactile sensors and artificial skin applications. 相似文献