公开(公告)号：US4881813A

公开(公告)日：1989-11-21

申请号：US196705

申请日：1988-05-20

申请人： Kee P. Koo ,  Frank Bucholtz ,  Anthony Dandridge

发明人： Kee P. Koo ,  Frank Bucholtz ,  Anthony Dandridge

IPC分类号： G01D5/353

CPC分类号： G01D5/35303

摘要： Three sampling circuits, a subtraction circuit, and a divider circuit cooate to sample an output signal from a nonlinear interferometric sensor at proper times, to subtract output signal samples to obtain a difference signal, and to divide an output signal sample into the difference signal to remove noise-induced modulation from the output signal.

摘要翻译： 三个采样电路，一个减法电路和一个分频电路合作，在适当的时间对来自非线性干涉测量传感器的输出信号进行采样，以减去输出信号样本以获得差分信号，并将输出信号采样分成差分信号 从输出信号中去除噪声引起的调制。

公开(公告)号：USH94H

公开(公告)日：1986-07-01

申请号：US795949

申请日：1985-11-07

申请人： Kee P. Koo

发明人： Kee P. Koo

IPC分类号： G01R33/032

CPC分类号： G01R33/0327

摘要： A fiber optic interferometer-type magnetic field sensor which uses an automatic feedback system to limit the range of the magnetic field experienced by the sensor element. A high frequency bias field is mixed with the external magnetic field to be measured and the resulting interferometer output signal is converted to an electric output signal. The electric output signal is mixed with a reference signal having the same frequency as the bias signal to form a baseband negative feedback signal which is converted to a magnetic field and mixed with the bias and external fields to provide automatic feedback.

公开(公告)号：US4591786A

公开(公告)日：1986-05-27

申请号：US641656

申请日：1984-08-17

申请人： Kee P. Koo ,  George H. Sigel, Jr.

发明人： Kee P. Koo ,  George H. Sigel, Jr.

IPC分类号： G01R33/022 ,  G01R33/032 ,  G01B9/02

CPC分类号： G01R33/0327 ,  G01R33/022

摘要： A fiber optic magnetic gradiometer for measuring both ac and dc magnetic field gradients. The gradiometer utilizes an optical interferometer with magnetostrictive magnetic field sensing elements in each of the interferometer arms. Ac and dc magnetic field biasing is achieved by disposing each of the magnetic field sensing elements within its own magnetic field coil and utilizing a variable dc current source for applying dc current to each magnetic coil. An ac current source at frequency w.sub.o connected across the circuits for the dc current sources is used in conjunction with a variable attenuator to control the ac bias to the respective magnetic coils. The detected output from the interferometer is processed either by bandpass filters or a spectrum analyzer to obtain the signal component at w.sub.o, which is proportional to the external dc gradient magnetic field, and at w.sub.o +w.sub.s, (where w.sub.s is external ac magnetic field frequency), which is proportional to the external ac magnetic field gradient.

摘要翻译： 用于测量交流和直流磁场梯度的光纤磁梯度计。 梯度计利用在每个干涉仪臂中具有磁致伸缩磁场感测元件的光学干涉仪。 通过将每个磁场感测元件设置在其自身的磁场线圈内并利用可变直流电流源来施加直流电流到每个电磁线圈来实现ac和dc磁场偏置。 连接在直流电流源的电路两端的交流电源与可变衰减器一起使用，以控制对各个磁性线圈的交流偏压。 来自干涉仪的检测输出通过带通滤波器或频谱分析仪进行处理，以获得与外部直流梯度磁场成比例的wo处的信号分量，并且在wo + ws（其中ws是外部交流磁场频率 ），其与外部交流磁场梯度成比例。

公开(公告)号：US5305075A

公开(公告)日：1994-04-19

申请号：US12140

申请日：1993-01-29

申请人： Frank Bucholtz ,  Kee P. Koo ,  Dominique M. Dagenais

发明人： Frank Bucholtz ,  Kee P. Koo ,  Dominique M. Dagenais

IPC分类号： G01R33/032 ,  G01B9/02

CPC分类号： G01R33/0327

摘要： The fiber-optic magnetostrictive transducer system consists of a sensing element having three dual-strip fiber optic magnetostrictive transducers bonded into a single fiber Mach-Zehnder interferometer operating single mode mounted in a symmetrical orthogonal geometry. The dual-strip fiber optic magnetostrictive transducers have predictable and consistent reproducibility and are comprised of a pair of field annealed metallic glass strips bonded to a coil of optical fiber. This structure is in turn mounted on a bobbin structure where the fiber ribbon is attached to the bobbin only at the two ends of the bobbin. This reduces the possible loading of the transducer due to friction between the optical fiber and the surface of the mounting structure and at the same time provide a long sensing fiber in contact with the magnetostrictive element for high sensitivity. The symmetrical orthogonal arrangement of the transducers minimizes magnetic crosstalk and the strip form of the transducer elements maintain high directional sensitivity.

摘要翻译： 光纤磁致伸缩传感器系统由具有三个双带光纤磁致伸缩传感器的感测元件组成，该双重带状光纤磁致伸缩传感器结合到以单对称的正交几何形式安装的单模马赫 - 曾德干涉仪中。 双带光纤磁致伸缩传感器具有可预测和一致的重现性，并且包括一对结合到光纤线圈的场退火的金属玻璃带。 这种结构又安装在线轴结构上，其中纤维带仅在线轴的两端附接到线轴。 这减少了由于光纤与安装结构的表面之间的摩擦而导致的传感器的可能负荷，并且同时提供了与磁致伸缩元件接触的长的感测光纤以实现高灵敏度。 传感器的对称正交布置使磁串扰最小化，传感器元件的条形保持高方向灵敏度。

公开(公告)号：US5243403A

公开(公告)日：1993-09-07

申请号：US767955

申请日：1991-09-30

申请人： Kee P. Koo ,  George H. Sigel, Jr. ,  Frank Bucholtz

发明人： Kee P. Koo ,  George H. Sigel, Jr. ,  Frank Bucholtz

IPC分类号： G01R33/02 ,  G01R33/032

CPC分类号： G01R33/0327 ,  G01R33/0206

摘要： A three-axis fiber optic vector magnetometer is provided for measuring bothhe direction and magnitude of a DC or low frequency magnetic field. The magnetometer includes an optical interferometer system including a sensing fiber arm disposed with three respective sensing portions perpendicular to one another and attached to a uni-directional sensor material. The interferometer system also includes a reference fiber arm and a laser light source for generating and introducing a laser light into both of the arms. Respective biasing devices generate a reference AC magnetic bias and a respective reference frequency in the three sensing portions. A detecting device detects a reference light signal from the reference fiber arm and the magnetically altered sensing light signal from the sensing fiber arm and forms an interferometer output signal. Respective separating devices then separate the respective magnetically induced interferometer signals at respective ones of the frequencies and produce a respective output signal indicative thereof. This output signal is thus indicative of the magnetic field strength in the respective direction and a vector sum of the strengths shows the magnetic field direction. Preferably, the sensor material is an annealed amorphous metallic glass strip and the separating means are lock-in amplifiers in their phase sensitive detection modes. The biasing devices are also preferably respective Helmholtz coils and a feedback system is provided for feeding back the output of the respective separating devices to the respective biasing devices.

摘要翻译： 提供三轴光纤矢量磁强计用于测量直流或低频磁场的方向和幅度。 磁力计包括光学干涉仪系统，该光学干涉仪系统包括感测纤维臂，该感测纤维臂设置有彼此垂直的三个相应感测部分，并附接到单向传感器材料。 干涉仪系统还包括参考光纤臂和激光光源，用于产生并将激光引入到两个臂中。 相应的偏置装置在三个感测部分中产生参考AC磁偏置和相应的参考频率。 检测装置检测来自参考纤维臂的参考光信号和来自感测纤维臂的磁改变的感测光信号，并形成干涉仪输出信号。 然后，相应的分离装置在各个频率处分离相应的磁感应干涉仪信号，并产生指示其的相应输出信号。 因此，该输出信号表示各方向的磁场强度，强度的矢量和表示磁场方向。 优选地，传感器材料是退火的非晶金属玻璃带，分离装置是其相敏检测模式的锁定放大器。 偏置装置还优选地是相应的亥姆霍兹线圈，并且提供反馈系统用于将各个分离装置的输出反馈到相应的偏置装置。

公开(公告)号：USH864H

公开(公告)日：1991-01-01

申请号：US464497

申请日：1990-01-12

申请人： Frank Bucholtz ,  Kee P. Koo ,  Anthony Dandridge ,  Alan B. Tveten

发明人： Frank Bucholtz ,  Kee P. Koo ,  Anthony Dandridge ,  Alan B. Tveten

IPC分类号： G01R33/032

CPC分类号： G01R33/0327

摘要： Improved passive and laser-conditioned magnetic field sensor of compact and integrated construction for enabling the detection of a magnetic field as well as an improved method of manufacture for assembling and selectively pretensioning a subassembly in order to provide an enhanced formation of the subassembly prior to use. The sensor is generally made up of a magnetic field sensing device, first and second fiber-optic elements, first and second couplers, a laser source and a combined detector and analysis means. The first and second couplers interconnect the first and second fiber-optic elements. The magnetic field sensing device is advantageously connected to one of the fiber-optic elements and is generally made up of a magneto-strictive material (MSM) of ribbon-like shape, a nonmagnetic substrate and a sensing element of optic fiber construction. This element is of predetermined and selective multistrand design between its ends and of generally serpentine shape. The sensing device is advantageously formed such that the MSM and the sensing element are uniformly and selectively pretensioned. As the result of this pretensioning, the MSM elongates when a magnetic field is detected thereby decreasing the elongation of the sensing element. Despite this decrease, the sensing element remains tensioned because of sufficient pretensioning and the phase shift in the laser as it is conducted through the optic fiber is detectable by the combined means.

公开(公告)号：US4603296A

公开(公告)日：1986-07-29

申请号：US610460

申请日：1984-05-15

申请人： Kee P. Koo ,  George H. Sigel, Jr.

发明人： Kee P. Koo ,  George H. Sigel, Jr.

IPC分类号： G01R33/032 ,  G01B9/02 ,  G02F1/29

CPC分类号： G01R33/0327

摘要： A fiber optic magnetometer for detecting DC magnetic fields includes a first optical fiber having a magnetostrictive jacket thereon which defines a sensing arm, and a second fiber defining a reference arm. A first AC magnetic field of frequency .omega..sub.o and a second AC field of frequency .omega..sub.s are imposed on the magnetostrictive jacket so as to cause a time varying optical path length change, having .omega..sub.o, (.omega..sub.o +.omega..sub.s), and (.omega..sub.o -.omega..sub.s) components in the sensing arm fiber. This induces a corresponding time varying phase shift, also having the above components, in light transmitted through the sensing arm fiber which is detected by a phase detector. The phase detector produces a signal proportional to the phase shift, this signal being passed to a lock-in amplifier set to amplify at .omega..sub.o. .omega..sub.s is sufficiently small such that the lock-in amplifier filters all components other than the .omega..sub.o, (.omega..sub.o +.omega..sub.s), and (.omega..sub.o -.omega..sub.s) components. The sum of these components changes in magnitude upon exposure of the magnetostrictive jacket to a DC field, thereby indicating the presence of a DC field. The lock-in amplifier output is plotted on an oscilloscope versus the second AC field of frequency .omega..sub.s to give a loop which shifts in position when the device is exposed to an external DC field.

摘要翻译： 用于检测直流磁场的光纤磁力计包括：第一光纤，其上具有限定感测臂的磁致伸缩护套，以及限定参考臂的第二光纤。 频率ωo的第一交流磁场和频率ω的第二AC场被施加在磁致伸缩套上，以便引起时变光路长度变化，具有ωω（ωω+ω）和ω 感测臂光纤中的零件。 这通过由相位检测器检测到的感测臂光纤透射的光在同样具有上述分量的情况下引起相应的时变相移。 相位检测器产生与相移成比例的信号，该信号被传递到锁定放大器，以在ωo上放大。 ωω足够小，使得锁定放大器滤除除ω，ω（ωω+ω）和（ωωω）分量之外的所有成分。 这些组件的总和在磁致伸缩套管暴露于DC场时的幅度发生变化，从而指示存在DC场。 锁定放大器输出绘制在示波器上，而不是频率ω的第二个AC场，以便当器件暴露于外部DC场时产生位移偏移的环路。

公开(公告)号：US4600885A

公开(公告)日：1986-07-15

申请号：US610463

申请日：1984-05-15

申请人： Kee P. Koo ,  Anthony Dandridge ,  Alan B. Tveten ,  George H. Sigel, Jr.

发明人： Kee P. Koo ,  Anthony Dandridge ,  Alan B. Tveten ,  George H. Sigel, Jr.

IPC分类号： G01R33/032 ,  G01R33/02

CPC分类号： G01R33/0327

摘要： A fiber optic magnetometer for detecting DC magnetic fields includes a first optical fiber having a magnetostrictive jacket thereon which defines a sensing arm, and a second fiber defining a reference arm. An AC magnetic field of frequency .omega..sub.o and constant amplitude is imposed on the magnetostrictive jacket so as to cause a time varying optical path length change, having an .omega..sub.o component, in the sensing arm fiber. This induces a corresponding time varying phase shift, also having an .omega..sub.o component, in light transmitted through the sensing arm fiber which is detected by a phase detector. The phase detector produces a signal proportional to the phase shift, this signal being passed to a lock-in amplifier set to amplify at .omega..sub.o. The lock-in amplifier produces an output signal proportional to the amplitude of the .omega..sub.o component, wherein this amplitude is proportional to any DC magnetic fields to which the device is exposed.

摘要翻译： 用于检测直流磁场的光纤磁力计包括：第一光纤，其上具有限定感测臂的磁致伸缩护套，以及限定参考臂的第二光纤。 在磁致伸缩套管上施加频率ωo和恒定幅度的交流磁场，从而在感测臂光纤中产生具有ωo分量的时变光程长度变化。 这通过相位检测器检测到的通过感测臂光纤传输的光在同一时间变化的相移中也产生ωω分量。 相位检测器产生与相移成比例的信号，该信号被传递到锁定放大器，以在ωo上放大。 锁定放大器产生与ωo分量的幅度成比例的输出信号，其中该幅度与装置所暴露的任何DC磁场成比例。