Use Single—chip Computer to Realize Automatic Compensation for Optical Fiber Sensors

Being directed againet two kinks of noise in optical fiber sensors,a sim-ple and effective method of automatic compensation for optical fiber sensors is presented.Not only the unstability effect of light source,but also zero drift of photoelectronic de-vices,can be eliminated or enormously restraned with the aid of this method.In another way,by using single-chip mrcrocomputer,the optical fiber sensor system fabricated is caonneted to a copmuter networks to realize an automatic compensation.     

Temperature Compensation for Double Fiber Bragg Grating Sensors

A novel double fiber Bragg grating(FBG) strain sensor configuration is presented. Temperature compensation method is based on double FBG moored on a rhombus frame. Through the theoretical analysis,the relation between relative shift of Bragg wavelength and the strain applied on the sensor is obtained,and the analytical expression of strain sensitivity coefficient is also given. The experiment results show that:in the strain range of 0～0.8 mm,the relation between the relative shift of Bragg wavelength and applied strain is linear,and the dispersion of double FBG wavelength at the range of -25 ℃～60 ℃ is 0～0.002 nm. The strain sensitivity of the displacement sensor configuration is 0.171 nm/με,and is nearly twice than that of single FC sensor.     

Properties of Single Mode Polymer Optical Fiber

The density, dynamic modulus, Young‘s modulus, tensile strength, extension properties, Fourier transform infrared spectrum and differential scanning calorimetry have been measured and discussed for single mode polymethyl--methacrylate optical fiber. The results show that the fiber can provide large strain range for polymeric optical fiber Bragg gratings.     

Optical Fiber Instrument for Single—point Multi—parameter Measurement

A novel kind of optical fiber instrument for two-channel measurement of temperature and displacement was developed.Four-channel quartz fiber optics were emplotyed to measure two-channel signals of temperature and displacement simultaneously, and the operating efficiency of this instrument was greatly improved.     

Two－color Optical Fiber Pyrometer

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Chairs＇ Introduction to APOS2008 The 1st Asia-Pacific Optical Fiber Sensors Conference

This special issue in the Journal of Electronic Science ＆ Technology of China （JESTC） contains the selected papers presented at the 1st Asia-Pacific Optical Fiber Sensors Conference （APOS2008） organized by University of Electronic Science and Technology of China and Chongqing University, China. This conference is supported by Ministry of Education of the People＇s Republic of China, National Nature Science Foundation of China （NSFC）, and Chinese Optics Society （COS）.     

Chairs’ Introduction to APOS2008——The 1st Asia-Pacific Optical Fiber Sensors Conference

This special issue in the Journal of Electronic Science & Technology of China (JESTC) contains the selected papers presented at the 1st Asia-Pacific Optical Fiber Sensors Conference (APOS2008) organized by University of Electronic Science and Technology of China and Chongqing University, China. This conference is supported by Ministry of Education of the People’s Republic of China, National Nature Science Foundation of China (NSFC), and Chinese Optics Society (COS).     

Measuring System for Interference Optical Fiber Acoustic Emission

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Explosion－insulated Full Optical Fiber Diferential－presure Measuring Instrument

Ｅｘｐｌｏｓｉｏｎ－ｉｎｓｕｌａｔｅｄＦｕｌＯｐｔｉｃａｌＦｉｂｅｒＤｉｆｅｒｅｎｔｉａｌ－ｐｒｅｓｕｒｅＭｅａｓｕｒｉｎｇＩｎｓｔｒｕｍｅｎｔ①ＺＨＥＮＧＤｅｚｈｏｎｇ，ＷＵＣｈａｎｇｑｉ，ＷＡＮＧＺｈｅｎｃｈｅｎ，ＬＩＺｕｏｆａｎｇ（Ｙａｎｓｈａ...     

A New Optical Fiber Loop System Used in Measurement of Dispersion Compensation Ability

ＡＮｅｗＯｐｔｉｃａｌＦｉｂｅｒＬｏｏｐＳｙｓｔｅｍＵｓｅｄｉｎＭｅａｓｕｒｅｍｅｎｔｏｆＤｉｓｐｅｒｓｉｏｎＣｏｍｐｅｎｓａｔｉｏｎＡｂｉｌｉｔｙＭａｎｕｓｃｒｉｐｔｒｅｃｅｉｖｅｄＤｅｃ．２４，１９９６．ＳｕｐｐｏｒｔｅｄｂｙＫｅｙＰｒｏｊｅｃｔ...     

用于计算机网的光纤时分复用系统

本文从计算机网的角度出发，介绍了一种数据时分复用系统，并讨论了它的局限性和扩展性。     

Two—color Optical Fiber Pyrometer

On the basis of thermal radiation from solid surface to measeure tem-perature,a new two-color optical fiber pyrometer is put forward.It gets two thermal radiation signals by the method of Y-type optical fiber and narrow band filter for indi-cation of the temperature,Si diode in used for photoelectric measurement and MCS-51 single-chip microcomputer for sampling and handling.The system can output in digital and can print out instantaneous value,peak value and valley,It has many advan-tages such as quick measurement,small objective,high precision,high sensitivity and non-emissivity compensation.in addition,the special circuit of this pyrometer and the es-tablishment of mathematics model are discussed.     

光纤参量振荡器的自动反馈控制技术研究

为了实现光纤参量振荡器(FOPO)的高精度稳定时钟信号提取,该文首次开展了基于闲频光功率的自动反馈控制实验,其中自动反馈控制单元由闲频光采集模块、自动控制信号处理模块以及延迟线驱动模块组成。测量了12.5 Gb/s归零(RZ)信号输入时自动反馈控制FOPO提取的时钟信号质量,其均方根(RMS)相位抖动值为0.92 ps,时钟提取精度明显高于之前的手动反馈控制系统。     

Explosion—insulated Full Optical Fiber Differential—pressure Measuring Instrument

The principles and features of the pressure-liquidometer using optical fiber sensor,which is suitable to use in dangerous areas,are described.The instrument is eapecially suitable for automatic detecting of pressure and liquid level in dangerous as large sacle oil tanker,cave oil tanker,civic liquid-gas tanker and so on.     

New Optical Fiber Pressure Sensor with Reflection Capsule

The ratio measurement by means of the sensing optical fiber and the re-ference fiber with different beginning positions,and the technique to improve the satbil-ity of the sensor are first described.Then the ability to restrain and compenate the in-terference the smae nature throught the double channel ration measurement is illustra-ted.Finally,the performance of sensor and its engineering desingh are discussed.     

光纤LAN技术概论

本文从系统分析的角度,对光纤LAN的传输媒介,拓扑结构,信道访问方式和网络体系结构等一系列问题进行了一些初步探讨.     

Optically—powered Optical Fiber Pressure Sensor of Diffused Silicon

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.     

Optically Powered Pressure Sensor with Optical Fiber Link

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.