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1.发明授权
公开(公告)号：US4697926A
公开(公告)日：1987-10-06
申请号：US699855
申请日：1985-02-08
申请人： Robert C. Youngquist , Janet L. Brooks , Kenneth A. Fesler , Cassius C. Cutler , Herbert J. Shaw
发明人： Robert C. Youngquist , Janet L. Brooks , Kenneth A. Fesler , Cassius C. Cutler , Herbert J. Shaw
CPC分类号： G01D5/35383
摘要： A distributed sensor system including an optical source having a short coherence length for optionally continuously monitoring each sensor in the system. In one preferred embodiment, an array of fiber-optic sensors are organized in a ladder configuration, with the sensors positioned in spaced relation and defining the rungs of the ladder. Light transmitted through the sensors is multiplexed onto a return arm of the ladder, with sensor spacing being such that interference between light from different sensors is prevented. The multiplexed signals are received by an optical fiber receiver which couples the multiplexed light with an interfering optical reference signal to produce a phase difference signal representing conditions influencing selected sensors. Embodiments are disclosed for use of either pulsed or continuous wave light sources. In another preferred embodiment, the sensors comprise a plurality of Mach-Zehnder interferometers connected in series configuration by a common optical fiber, which provides multiplexed output signals from the sensors to a plurality of Mach-Zehnder interferometers comprising receivers. The optical path length differences between the arms of each of the sensors are selected to prevent interference between the multiplexed sensor output signals from various sensors. The optical path lengths through the sensors and receivers are structured so that each receiver produces a phase difference signal relating to conditions affecting light transmission through a specific sensor. A phase and amplitude modulation technique is disclosed for providing heterodyned output signals from the distributed sensor system.
摘要翻译： 一种分布式传感器系统，包括具有短相干长度的光源，用于可选地连续监测系统中的每个传感器。 在一个优选实施例中，光纤传感器阵列以梯形结构组织，传感器以间隔关系定位并限定梯子的梯级。 通过传感器传输的光被多路复用到梯子的返回臂上，传感器间隔使得防止来自不同传感器的光之间的干扰。 复用的信号由光纤接收器接收，光纤接收器将复用的光与干涉光参考信号耦合，以产生表示影响所选传感器的条件的相位差信号。 公开了使用脉冲或连续波光源的实施例。 在另一个优选实施例中，传感器包括通过公共光纤串联配置的多个马赫 - 曾德干涉仪，其将来自传感器的多路复用输出信号提供给包括接收器的多个马赫 - 曾德干涉仪。 选择每个传感器的臂之间的光程长度差以防止来自各种传感器的多路传感器输出信号之间的干扰。 通过传感器和接收器的光路长度被构造成使得每个接收器产生与影响通过特定传感器的光透射的条件相关的相位差信号。 公开了一种用于从分布式传感器系统提供外差输出信号的相位和幅度调制技术。
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公开(公告)号：US4778237A
公开(公告)日：1988-10-18
申请号：US618032
申请日：1984-06-07
CPC分类号： G02B6/266 , G02B6/2821 , G02B6/2826 , G02B6/2861 , G02F1/3523
摘要： A fiber optic saturable absorber for processing optical signals comprises an optical fiber from which a portion of the cladding is removed to form a facing surface. A light-absorbing substance having non-linear light-absorbing characteristics is applied to the facing surface such that a portion of the optical signal energy is transferred from the fiber to the substance where it is absorbed. The device selectively attenuates the optical signal and noise, and can be used to reduce pulse waveform distortion caused by pulse broadening and by amplification of system noise.
摘要翻译： 用于处理光信号的光纤可饱和吸收器包括光纤，其中去除了包层的一部分以形成面对表面。 具有非线性光吸收特性的光吸收物质被施加到相对表面，使得光信号能量的一部分从纤维转移到被吸收的物质。 该器件选择性地衰减光信号和噪声，可用于减少由脉冲展宽和系统噪声放大引起的脉冲波形失真。
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3.发明授权Fiber optic modal coupler, interferometer and method of coupling spatial modes using same 失效光纤模态耦合器，干涉仪和使用它们耦合空间模式的方法
公开(公告)号：US4768851A
公开(公告)日：1988-09-06
申请号：US884871
申请日：1986-07-09
CPC分类号： G02B6/29352 , G02B6/2726 , G02B6/2821 , G02F1/0134 , Y10S359/90
摘要： A modal coupler, for coupling between first and second order modes of an optical fiber, comprises a single continuous strand of optical fiber, and a device for applying stress to the optical fiber at spaced intervals along the fiber. The stress deforms the fiber and abruptly changes the fiber geometry at the beginning and end of each stressed region. The change in fiber geometry causes coupling of light from the fundamental mode to the second order mode. The coupler, under certain conditions, exhibits polarization dependence, and thus, it may be utilized as a fiber optic polarizer. In addition, the device couples coherently, and may be used in interferometric systems.
摘要翻译： 用于在光纤的一阶和二阶模之间耦合的模式耦合器包括单个连续的光纤链，以及用于沿光纤以间隔间隔向光纤施加应力的装置。 应力使纤维变形，并突然改变每个应力区域的开始和结束处的纤维几何形状。 光纤几何形状的改变导致从基模到二阶模的耦合。 在一定条件下，耦合器具有偏振相关性，因此可用作光纤偏振器。 此外，该装置相干耦合，并可用于干涉系统。
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4.发明授权Birefringent fiber narrowband polarization coupler and method of coupling using same 失效双折射光纤窄带偏振耦合器及其耦合方法
公开(公告)号：US4801189A
公开(公告)日：1989-01-31
申请号：US161375
申请日：1988-02-22
CPC分类号： G02B6/274 , G02B6/2766 , G02B6/2821 , G02F1/0134 , Y10S359/90
摘要： There is disclosed herein a fiber optic directional coupler for coupling light between two polarization modes. A highly birefringent fiber optic waveguide is positioned on a flat polished surface with either of the principal axes of birefringence oriented at an angle, preferably 45.degree., to the vertical. A ridged block is then pressed down on the fiber. The ridges of the block have longitudinal axes transverse to the longitudinal axis of the fiber. The width of the ridge faces is one-half beat length, and the spacing between the ridges in also one-half beat length. The stressed regions caused by the ridges cause coupling of light traveling in one polarization mode into the other polarization mode by abrupt shifting of the axes of birefringence at the boundaries of the stressed regions.
摘要翻译： 这里公开了用于在两个偏振模式之间耦合光的光纤定向耦合器。 高度双折射的光纤波导位于平坦抛光表面上，双折射的主轴线与垂直方向成一定角度，最好是45°。 然后将一个脊状块压在纤维上。 块的脊具有横向于纤维的纵向轴线的纵向轴线。 脊面的宽度为半节拍长度，脊之间的间距也为半节拍长度。 由脊部引起的应力区域通过在应力区域的边界处的双折射轴的突然移位而导致以一种偏振模式行进的光耦合到另一种偏振模式。
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5.发明授权Single mode fiber optic single sideband modulator and method of frequency shifting using same 失效单模光纤单边带调制器和使用相同方式进行频移
公开(公告)号：US4792207A
公开(公告)日：1988-12-20
申请号：US50762
申请日：1987-05-15
CPC分类号： G02F1/0134 , G02B6/2821 , G02F1/125 , Y10S359/90
摘要： A fiber optic frequency shifter comprising two waveguides having different indices of refraction. In some embodiments the waveguides are two modes of propagation in one fiber. Plural distributed coupling ridges, or electrodes mounted adjacent piezoelectric materials, are independently driven to apply sinusoidally varying forces to the fiber. In some embodiments, the phase relationship of the driving signals for the electrodes or ridges is such that a travelling acoustic wave is launched in the fiber. In other embodiments, regions of stress in the fiber are created by an acoustic wave coupled into the fiber from a transducer coupled to an acoustic medium surrounding the fiber. The input carrier light is shifted in frequency by the frequency of the acoustic wave.
摘要翻译： 一种光纤移频器，包括具有不同折射率的两个波导。 在一些实施例中，波导是在一个光纤中的两种传播模式。 多个分布耦合脊或邻近压电材料安装的电极被独立地驱动以向光纤施加正弦变化的力。 在一些实施例中，用于电极或脊的驱动信号的相位关系使得行进声波在光纤中发射。 在其他实施例中，光纤中的应力区域是由耦合到围绕光纤的声学介质的传感器耦合到光纤中的声波产生的。 输入载波的频率以声波的频率移动。
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6.发明授权Distributed sensor and method using coherence multiplexing of fiber-optic interferometric sensors 失效分布式传感器和使用光纤干涉传感器相干多路复用的方法
公开(公告)号：US4699513A
公开(公告)日：1987-10-13
申请号：US738678
申请日：1985-05-28
申请人： Janet L. Brooks , Moshe Tur , Robert C. Youngquist , Byoung Y. Kim , Robert H. Wentworth , Herbert J. Shaw , Kjell Blotekjaer
发明人： Janet L. Brooks , Moshe Tur , Robert C. Youngquist , Byoung Y. Kim , Robert H. Wentworth , Herbert J. Shaw , Kjell Blotekjaer
IPC分类号： G01D21/00 , G01D5/26 , G01D5/353 , G01H7/00 , G01H9/00 , G01K11/00 , G01L1/00 , G01N21/00 , G01N21/17 , G02B6/00 , G02B6/14 , G02B6/28 , G08C15/00 , H04J14/00 , G01B9/02
CPC分类号： G01D5/35383 , G02B6/14 , G02B6/2821 , G02B6/2826 , G02B6/283 , G02B6/2843 , G02B6/2861 , H04J14/002
摘要： A distributed sensor system including an optical source having a short coherence length for optionally continuously monitoring each sensor in the system. In one preferred embodiment, an array of fiber-optic sensors are organized in a ladder configuration, with the sensors positioned in spaced relation and defining the rungs of the ladder. Light transmitted through the sensors is multiplexed onto a return arm of the ladder, with sensor spacing being such that interference between light from different sensors is prevented. The multiplexed signals are received by an optical fiber receiver which couples the multiplexed light with an interfering optical reference signal to produce a phase difference signal representing conditions influencing selected sensors. Embodiments are disclosed for use of either pulsed or continuous wave light sources. In another preferred embodiment, the sensors comprise a plurality of interferometers connected in series configuration by a common optical fiber, which provides multiplexed output signals from the sensors to another plurality of interferometers comprising receivers. Functional equivalents of the series configuration provide sensors and receivers comprising birefringent or two-mode fiber. The optical path length differences between each pair of sensor arms are selected to prevent interference between the multiplexed sensor output signals from the various sensors. The optical path lengths through the sensors and receivers are structured so that each receiver produces a phase difference signal relating to conditions affecting light transmission through a specific sensor. A phase and amplitude modulation technique is disclosed for providing heterodyned output signals from the distributed sensor system.
摘要翻译： 一种分布式传感器系统，包括具有短相干长度的光源，用于可选地连续监测系统中的每个传感器。 在一个优选实施例中，光纤传感器阵列以梯形结构组织，传感器以间隔关系定位并限定梯子的梯级。 通过传感器传输的光被多路复用到梯子的返回臂上，传感器间隔使得防止来自不同传感器的光之间的干扰。 复用的信号由光纤接收器接收，光纤接收器将复用的光与干涉光参考信号耦合，以产生表示影响所选传感器的条件的相位差信号。 公开了使用脉冲或连续波光源的实施例。 在另一个优选实施例中，传感器包括通过公共光纤串联配置的多个干涉仪，其将来自传感器的多路复用输出信号提供给包括接收器的另外多个干涉仪。 串联配置的功能等同物提供包括双折射或双模光纤的传感器和接收器。 选择每对传感器臂之间的光程长度差以防止来自各种传感器的多路传感器输出信号之间的干扰。 通过传感器和接收器的光路长度被构造成使得每个接收器产生与影响通过特定传感器的光透射的条件相关的相位差信号。 公开了一种用于从分布式传感器系统提供外差输出信号的相位和幅度调制技术。
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7.发明授权Sensor array and method of selective interferometric sensing by use of coherence synthesis 失效通过使用相干合成的传感器阵列和选择性干涉测量方法
公开(公告)号：US4818064A
公开(公告)日：1989-04-04
申请号：US100483
申请日：1987-09-24
CPC分类号： G01H9/004 , G01D5/35383 , Y10S359/90
摘要： A sensor array and method for remotely monitoring environmental effects on a selected sensor. In a sensor array comprising a plurality of interferometers, an optical signal of a selected configuration is provided so that portions of the optical signal are propagated through the interferometers. The optical signal configuration causes optical signal portions which have traveled the same signal path, except where separated on signal paths in a selected interferometer, to coherently mix when combined at an output of the selected interferometer. No other optical signal portions in the sensor array will coherently mix. The optical signal comprises plural components such as side bands which are configured to form a power spectrum defining an optical signal coherence function having a maximum which repeats periodically at a rate substantially corresponding to optical signal travel time difference in the selected interferometer. Also, the coherence function has minimums or zero values at times such that intervals between various minimums substantially correspond to optical signal travel time differences through non-selected interferometers, thus precluding coherent mixing of optical signal portions emerging from those non-selected interferometers. By modifying characteristics of the optical signal components, one may change the repetition period of the coherence function maximum and of selected coherence function minimums to produce coherent mixing of signal portions from another interferometer while precluding coherent mixing of signals from all other interferometers, including the previously selected interferometer. Accordingly, a given sensor may be selected from monitoring, to the exclusion of all others.
摘要翻译： 用于远程监测所选传感器的环境影响的传感器阵列和方法。 在包括多个干涉仪的传感器阵列中，提供所选配置的光信号，使得光信号的部分通过干涉仪传播。 光信号配置导致已经行进相同信号路径的光信号部分，除了在所选择的干涉仪中的信号路径上分离的情况下，当在所选择的干涉仪的输出处被组合时相干混合。 传感器阵列中没有其他光信号部分将相干混合。 光信号包括诸如边带的多个组件，其被配置为形成定义具有最大值的光信号相干函数的功率谱，该最大值以基本上对应于所选干涉仪中的光信号行进时间差的速率周期性地重复。 此外，相干函数在时间上具有最小值或零值，使得各种最小值之间的间隔基本上对应于通过未选择的干涉仪的光信号行进时间差，从而排除从那些未选择的干涉仪出现的光信号部分的相干混合。 通过修改光信号分量的特性，可以改变相干函数最大值和所选相干函数最小值的重复周期，以产生来自另一干涉仪的信号部分的相干混合，同时排除来自所有其它干涉仪的信号的相干混合，包括先前 选择干涉仪。 因此，可以选择给定的传感器来监视所有其他传感器。
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8.发明授权
公开(公告)号：US4735485A
公开(公告)日：1988-04-05
申请号：US581176
申请日：1984-02-17
IPC分类号： G02B6/00 , G02B6/28 , G02F1/01 , G02F1/11 , G02F1/125 , G02F1/23 , G02F1/25 , G02F2/02 , G02B6/02 , B32B31/00
CPC分类号： G02F1/0134 , G02B6/2821
摘要： A fiber optic frequency shifter comprises an optical fiber having two propagation modes and an acoustic transducer for generating an acoustic wave. The transducer is positioned relative to the fiber to cause the wave fronts of the acoustic wave to acoustically contact the fiber at an angle of incidence which is less than 90.degree. greater than 0.degree.. Preferably, the wavelength of the acoustic wave is substantially equal to the beat length of the fiber times the sine of the angle of incidence.
摘要翻译： 光纤移频器包括具有两个传播模式的光纤和用于产生声波的声换能器。 传感器相对于光纤定位，使得声波的波前以小于90°的0°以上的入射角与光纤以声学接触。 优选地，声波的波长基本上等于光纤的拍子长度乘以入射角的正弦。
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公开(公告)号：US20110133727A1
公开(公告)日：2011-06-09
申请号：US12961344
申请日：2010-12-06
IPC分类号： G01B7/14
CPC分类号： G01D5/2006
摘要： An inductive position sensor uses three inductors. First and second inductors are separated by a fixed distance with the first inductor's axial core and second inductor's axial core maintained parallel to one another. A third inductor is disposed between the first and second inductors with the third inductor's axial core being maintained parallel to those of the first and second inductors. The combination of the first and second inductors are configured for relative movement with the third inductor's axial core remaining parallel to those of the first and second inductors as distance changes from the third inductor to each of the first inductor and second inductor. In operation, a source supplies an oscillating current to at least one of the three inductors, while another device measures voltage induced in at least one of the three inductors not supplied with the oscillating current. The voltage so-induced is indicative of an amount of the relative movement between the third inductor and the combination of the first and second inductors.
摘要翻译： 感应位置传感器使用三个电感器。 第一和第二电感器与第一电感器的轴芯和第二电感器的轴心保持彼此平行的固定距离分开。 第三电感器设置在第一和第二电感器之间，其中第三电感器的轴芯保持与第一和第二电感器的轴芯平行。 第一和第二电感器的组合被配置为相对运动，其中第三电感器的轴芯保持与第一和第二电感器的轴芯平行，因为距离第三电感器到第一电感器和第二电感器中的每一个的距离变化。 在操作中，源将振荡电流提供给三个电感器中的至少一个，而另一个器件测量不提供有振荡电流的三个电感器中的至少一个感应的电压。 所感应的电压表示第三电感器与第一和第二电感器的组合之间的相对移动量。
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公开(公告)号：US5861755A
公开(公告)日：1999-01-19
申请号：US552456
申请日：1995-11-06
CPC分类号： G01F1/74 , G01F1/64 , G01N27/221 , G01N27/226
摘要： A quality and/or flow meter employs a capacitance probe assembly for measuring the dielectric constant of flow stream, particularly a two-phase flow stream including liquid and gas components. The dielectric constant of the flow stream varies depending upon the volume ratios of its liquid and gas components, and capacitance measurements can therefore be employed to calculate the quality of the flow, which is defined as the volume ratio of liquid in the flow to the total volume ratio of gas and liquid in the flow. By using two spaced capacitance sensors, and cross-correlating the time varying capacitance values of each, the velocity of the flow stream can also be determined. A microcontroller-based processing circuit is employed to measure the capacitance of the probe sensors. The circuit employs high speed timer and counter circuits to provide a high resolution measurement of the time interval required to charge each capacitor in the probe assembly. In this manner, a high resolution, noise resistant, digital representation of each of capacitance value is obtained without the need for a high resolution A/D converter, or a high frequency oscillator circuit. One embodiment of the probe assembly employs a capacitor with two ground plates which provide symmetry to insure that accurate measurements are made thereby.
摘要翻译： 质量和/或流量计采用电容探针组件来测量流动流的介电常数，特别是包括液体和气体组分的两相流动流。 流量的介电常数根据其液体和气体组分的体积比而变化，因此可以采用电容测量来计算流量的质量，其定义为流体中液体与总量之间的体积比 气体和液体的流量体积比。 通过使用两个间隔的电容传感器，并且互相关联每个的时变电容值，也可以确定流动流的速度。 采用基于微处理器的处理电路来测量探头传感器的电容。 该电路使用高速定时器和计数器电路来提供对探针组件中每个电容器充电所需的时间间隔的高分辨率测量。 以这种方式，不需要高分辨率A / D转换器或高频振荡器电路就能获得每个电容值的高分辨率，抗噪声的数字表示。 探针组件的一个实施例采用具有两个接地板的电容器，其提供对称性以确保由此进行准确的测量。
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