共查询到20条相似文献,搜索用时 0 毫秒
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Fearn L.A. Bartoo M.L. Myers J.A. Pollack G.H. 《IEEE transactions on bio-medical engineering》1993,40(11):1127-1132
A force transducer has been developed for use in force measurement of skeletal muscle myofibrils. The transducer is suitable for measurement of passive and contractile forces in a range up to 200 μg, with 1 μg resolution. It is based upon the operating principle of the deflection of an optical fiber of known compliance, sensed by the differential illumination of two phototransistors. Attractive features include ease of operation and specimen mounting, high bandwidth, adaptability for different force ranges, and simple and inexpensive construction 相似文献
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Miniaturized pressure transducer intended for intravascular use 总被引:2,自引:0,他引:2
L H Lindstr?m 《IEEE transactions on bio-medical engineering》1970,17(3):207-219
A pressure transducer utilizing an electrooptical method is described. As the transducer is primarily intended for intravascular use, it has been given the form of a catheter with the pressure-sensing part at the one end and the necessary bulky components at the other end. A light guide of glass fibers inside the catheter transports light from a light source to the measuring tip. Here the pressure variations affect a movable membrane which reflects a variable amount of light into another light guide leading to a photodetector. The variations in the signal from the detector are thus proportional to the applied pressure. The main part of the paper is concerned with a theoretical investigation of the principle for transducers of this type. This analysis gives relationships between the geometry of the measuring tip, the number of glass fibers, and their distribution, material constants, and signal parameters. Using these relations, it is possible to arrive at the fundamental limitations of the method, particularly in regard to the miniaturization. Furthermore, some temperature effects which are generally neglected, are analyzed. 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1977,65(12):1670-1678
This paper is a tutorial review of the theory and practice of receiver design for optical fiber communication systems. Topics discussed include fundamental limitations on performance; design and performance limitations of laboratory receivers; and practical design trade-offs and their effects on the performance of real system receivers. 相似文献
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This paper presents the reliability test results for LD modules, optical couplers, and APD modules, which are fabricated through methods for achieving and assuring a high degree of reliability for use in 400-Mbit/s submarine optical fiber transmission systems. In particular, the paper presents methods for evaluating the optical component reliability as well as an investigation into the degradation factors in the coupling circuits. From the reliability test results obtained, the paper also discusses the mechanism and test acceleration of wear-out degradation following reliability tests conducted for more than 8000 h on the fabricated optical components. These optical components are consequently confirmed to be highly reliable for a system life of 25 years. 相似文献
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Nishida Y. Fujiura K. Hoshino K. Shimizu M. Yamada M. Nakagawa K. Ohishi Y. 《Photonics Technology Letters, IEEE》1999,11(12):1596-1598
We report reliability test results for a fluoride fiber module. We developed a sealed fluoride fiber module for practical optical fiber amplifier use. Trouble-free damp heat storage and low-temperature storage for 5000 h and trouble-free temperature cycling and temperature-humidity cycling tests revealed that our fluoride fiber module has long-term stability under practical environmental conditions 相似文献
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Rasmussen T. Bjarklev A. Lumholt O. Obro M. Pedersen B. Povlsen J.H. Rottwitt K. 《Photonics Technology Letters, IEEE》1992,4(1):49-51
The waveguide parameters for a Nd-doped fluoride (Nd:ZBLANP) fiber amplifier have been optimized for small-signal and booster operation using an accurate numerical model. The optimum cutoff wavelength is shown to be 800 nm and the numerical aperture should be made as large as possible. Around 80% booster quantum conversion efficiency can be reached for an input power of 10 dBm and a pump power of 100 mW by the use of one filter 相似文献
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The characteristics of photonic bandgaps and the transmission/reflection of guided optical waves in the magneto-optic fiber Bragg grating (MFBG) are theoretically investigated for the first time. The polarization-mode conversion resulting from the Faraday effect may change the width of the pure bandgap, or even lead to a couple of photonic semitransparent frequency band (STB) for sufficiently large magneto-optical-to-grating coupling ratio (MGR). Within the STBs, the transmittivity and reflectivity are equal and then the MFBG can serve as a 3 dB light beam splitter. Based on the sensitivity of MFBG spectral lines to the magneto-optic (MO) coupling coefficient, a novel high-resolution magnetic field sensor capable of up to 0.01 nm/(kA/m) is predicted. According to the dependency of nonlinear transmission or reflection on the MO effects, a new class of MFBG-based nonlinear optical switches under an appropriate MO bias may also be achieved with applications to flexible and controllable optical signal processing. 相似文献
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A semiconductor pressure transducer consisting of a sensing resistor implanted into a silicon membrane as an elastic mechanical element is studied by the modulation polarimetry technique. Internal mechanical stresses are detected. The coordinate distributions of uniaxial stresses are measured in two cases: stresses remaining from local crystal doping inhomogeneities and stresses caused by heating by flowing current. The coordinate distribution of the temperature caused by the heat flux released by the resistor current is determined by double integration of the stress function, taking into account corresponding boundary conditions. 相似文献
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A theory is presented on the deformation of jacketed fibers due to lateral pressure, and its influence on microbending losses is assessed. This analysis, which is based on the theory Of elasticity, helps to clarify how lateral pressure and the structure of the fiber jacket conspire to cause excess fiber losses. Periodic pressure distributions with certain unfavorable period lengths are shown to lead to a pronounced enhancement of excess losses. 相似文献
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Xiaodong Wang Baoqing Li Harry T. Roman Kenneth R. Farmer 《Microelectronics Journal》2006,37(1):50-56
The design guidelines for micro diaphragm-type pressure sensors have been established by characterization of the relationships among diaphragm thickness, side length, sensitivity, and resonant frequency. According to the study, the thickness need to be thin and the side length need to be small in order to get the sensitive diaphragm with high resonant frequency. A Fabry-Perot based pressure sensor has been designed based on the guidelines, fabricated and characterized. In principle, the sensor is made according to Fabry-Perot interference, which is placed on a micro-machined rectangular silicon membrane as a pressure-sensitive element. A fiber-optic readout scheme has been used to monitor sensor membrane deflection. The experimental results show that the sensor has a very high sensitivity of 28.6 mV/Pa, resolution of 2.8 Pa, and up to 91 kHz dynamic response. 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1969,57(8):1433-1434
Several simple pressure transducers have been built by using heterode strain sensors evaporated directly onto a pressure diaphragm. The performance of these units indicates that pressure transducers are a feasible area of application for the heterode strain sensor, and that such transducers are potentially inexpensive and easily adapted to a variety of pressure ranges. 相似文献
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纳米薄膜与光纤的结合为新型感测提供了各种潜在可能.为了分析温度敏感薄膜的膜系设计及其对光纤温度传感器传感特性的影响,根据光学薄膜理论和光纤传感器的温度感测原理,探讨了光纤温度传感器中敏感薄膜的膜系设计,并构建了薄膜型光纤传感器的温度传感特性模型.以测试系统的参数、性能以及其对干涉光谱的要求为基础,设计了对称性较好的法布... 相似文献
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Intramodal contributions in measurements of optical-fiber bandwidth are investigated theoretically and experimentally in the quasimonochromatic case. A relation is established between the intramodal transfer function and a possibly non-Gaussian source spectrum, which may also vary with modulation frequency. By considering the latter variation in particular, we are able to predict the intramodal length dependence and show how it may deviate from that of a conventional approach. 相似文献