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公开(公告)号：US5224182A
公开(公告)日：1993-06-29
申请号：US751738
申请日：1991-08-29
CPC分类号： G01H9/004 , G01B11/18 , G01D5/35309 , G01D5/3538
摘要： Tapered two-mode optic fibers are used as sensors with sensitivity varying as a function of length. The optical fiber sensors act as vibrational-mode filters thereby performing initial signal processing of the sensor signal. The sensors are based on the differential propagation constant in a two-mode fiber that is directly dependent on the normalized frequency or V-number. Tapering the fiber changes the V-number and hence can change the sensitivity of the sensor along its length. By choosing an appropriate weighting function in the manufacture of the sensor, it is possible to implement vibrational-mode analysis, vibrational-mode filtering and other functions that are critical in control system applications.
摘要翻译： 锥形双模光纤被用作灵敏度随长度变化的传感器。 光纤传感器用作振动模式滤波器，由此执行传感器信号的初始信号处理。 传感器基于直接取决于归一化频率或V数的双模光纤中的差分传播常数。 纤维的锥度改变了V号，因此可以改变传感器沿其长度的灵敏度。 通过在传感器的制造中选择适当的加权函数，可以实现在控制系统应用中至关重要的振动模式分析，振动模式滤波和其他功能。
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2.发明授权
公开(公告)号：US5301001A
公开(公告)日：1994-04-05
申请号：US834674
申请日：1992-02-12
CPC分类号： G01D5/268
摘要： An extrinsic Fizeau fiber optic sensor comprises a single-mode fiber, used as an input/output fiber, and a multimode fiber, used purely as a reflector, to form an air gap within a silica tube that acts as a Fizeau cavity. The Fresnel reflection from the glass/air interface at the front of the air gap (reference reflection) and the reflection from the air/glass interface at the far end of the air gap (sensing reflection) interfere in the input/output fiber. The two fibers are allowed to move in the silica tube, and changes in the air gap length cause changes in the phase difference between the reference reflection and the sensing reflection. This phase difference is observed as changes in intensity of the light monitored at the output arm of a fused biconical tapered coupler. The extrinsic Fizeau fiber optic sensor behaves identically whether it is surface mounted or embedded, which is unique to the extrinsic sensor in contrast to intrinsic Fabry-Perot sensors. The sensor may be modified to provide a quadrature phase shift extrinsic Fizeau fiber optic sensor for the detection of both the amplitude and the relative polarity of dynamically varying strain. The quadrature light signals may be generated by either mechanical or optical means. A plurality of the extrinsic sensors may connected in cascade and multiplexed to allow monitoring by a single analyzer.
摘要翻译： 外部Fizeau光纤传感器包括用作输入/输出光纤的单模光纤，以及完全用作反射器的多模光纤，在作为Fizeau腔的硅胶管内形成气隙。 来自气隙前面的玻璃/空气界面的菲涅尔反射（参考反射）和来自气隙远端的空气/玻璃界面的反射（感测反射）干扰输入/输出光纤。 允许两根纤维在石英管中移动，并且气隙长度的变化引起参考反射和感测反射之间的相位差的变化。 该相位差被观察为在熔融双锥形锥形耦合器的输出臂处监视的光的强度的变化。 外部Fizeau光纤传感器的表现相同，无论是表面安装还是嵌入式，与内在的法布里 - 珀罗传感器相反，外部传感器是独一无二的。 可以修改传感器以提供正交相移外在Fizeau光纤传感器，用于检测动态变化应变的振幅和相对极性。 正交光信号可以通过机械或光学方式产生。 多个外部传感器可以级联并多路复用以允许通过单个分析器进行监视。
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公开(公告)号：US5448673A
公开(公告)日：1995-09-05
申请号：US106274
申请日：1993-08-12
申请人： Kent A. Murphy , Michael F. Gunther , Angela J. Plante , Veerendra B. Vuppala , Mallika B. Sen , Nirmal Velayudhan , Richard O. Claus
发明人： Kent A. Murphy , Michael F. Gunther , Angela J. Plante , Veerendra B. Vuppala , Mallika B. Sen , Nirmal Velayudhan , Richard O. Claus
CPC分类号： G02B6/2835 , G02B6/2856
摘要： Uniformity of optical coupling of optical elements such as star couplers and splitters is improved by heat treatment which causes dopants in the core of an optical fiber to diffuse into material from the cladding layer of the optical fibers from which the optical element is formed, resulting in a substantially homogeneous interior region of the star coupler or splitter. Increased lossiness of the optical element thus formed may be limited by termination of the heat treatment before dopant diffusion reaches equilibrium throughout the fibers so that a portion of the cladding layer of the fibers remains surrounding the substantially homogeneous region where the fibers have been fused together.
摘要翻译： 通过热处理改善诸如星形耦合器和分离器之类的光学元件的光耦合的均匀性，这使得光纤的芯中的掺杂剂从形成光学元件的光纤的包层扩散到材料中，导致 星形耦合器或分离器的基本均匀的内部区域。 由此形成的光学元件的增加的损耗可以通过在掺杂剂扩散在整个纤维之间达到平衡之前终止热处理来限制，使得纤维的包层的一部分保持围绕着纤维已经熔合在一起的基本均匀的区域。
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4.发明授权
公开(公告)号：US5216731A
公开(公告)日：1993-06-01
申请号：US777669
申请日：1991-10-15
IPC分类号： G02B6/28
CPC分类号： G02B6/2856
摘要： Optic fiber coupler fabrication stations allow one-step packaging and reduce fabrication time. The optic fiber coupler fabrication stations produce a single piece construction of the coupler package with improved uniformity. Two linear translation stages are driven in opposing directions using left and right hand threaded rods connected to a common drive shaft driven by a small electric motor. Fibers to be coupled are clamped into the station to provide the necessary tension during the tapering process. The fibers are tied together using cotton thread, and an oxy-propane torch is used to fuse the fibers together while the two translation stages pull the fibers to form a biconical tapered region in the fibers.
摘要翻译： 光纤耦合器制造站允许一步包装并缩短制造时间。 光纤耦合器制造站产生具有改进的均匀性的耦合器封装的单件结构。 使用连接到由小型电动机驱动的公共驱动轴的左右螺纹杆，在相反的方向上驱动两个线性平移级。 要联接的纤维被夹紧在工位中，以在渐缩过程中提供必要的张力。 使用棉线将纤维连接在一起，并且使用氧丙烷炬将纤维熔合在一起，而两个平移级拉动纤维以在纤维中形成双锥形锥形区域。
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公开(公告)号：US5809189A
公开(公告)日：1998-09-15
申请号：US523596
申请日：1995-09-05
申请人： Kent A. Murphy , Michael F. Gunther , Angela J. Plante , Veerendra B. Vuppala , Mallika B. Sen , Nirmal Velayudhan , Richard O. Claus
发明人： Kent A. Murphy , Michael F. Gunther , Angela J. Plante , Veerendra B. Vuppala , Mallika B. Sen , Nirmal Velayudhan , Richard O. Claus
CPC分类号： G02B6/2835 , G02B6/2856
摘要： Uniformity of optical coupling of optical elements such as couplers and splitters is improved by heat treatment which causes dopants in the core of an optical fiber to diffuse into material from the cladding layer of the optical fibers from which the optical element is formed, resulting in a substantially homogeneous interior region of the star coupler or splitter. Increased lossiness of the optical element thus formed may be limited by termination of the heat treatment before dopant diffusion reaches equilibrium throughout the fibers so that a portion of the cladding layer of the fibers remains surrounding the substantially homogeneous region where the fibers have been fused together. Dopant diffusion is constrained to a substantially radial direction in each fiber by uniformity of heating over a region where at least two fibers are twisted together. Thus dopant diffusion is highly repeatable and can be readily regulated to provide highly selective, wavelength-dependent coupling between fibers, particularly for multiplexing and demultiplexing applications.
摘要翻译： 通过热处理改善了诸如耦合器和分离器之类的光学元件的光耦合的均匀性，其使得光纤芯中的掺杂剂从形成光学元件的光纤的包覆层扩散到材料中，导致 星形耦合器或分离器的基本均匀的内部区域。 由此形成的光学元件的增加的损耗可以通过在掺杂剂扩散在整个纤维之间达到平衡之前终止热处理来限制，使得纤维的包层的一部分保持围绕着纤维已经熔合在一起的基本均匀的区域。 通过在至少两根纤维被扭绞在一起的区域上的加热均匀性，掺杂剂扩散被限制在每个纤维中基本上径向的方向。 因此，掺杂剂扩散是高度可重复的，并且可以容易地调节以提供光纤之间的高选择性，波长依赖性耦合，特别是对于复用和解复用应用。
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6.发明授权
公开(公告)号：US5339374A
公开(公告)日：1994-08-16
申请号：US67868
申请日：1993-05-26
CPC分类号： G02B6/2856
摘要： The fibers are bound together about 1 cm apart. An oxy-propane torch is used to heat the fibers so that they fuse together. At the same time, the two relatively movable translational stages to which the fibers are clamped are pulled apart to form a biconical tapered region in the fibers. The fibers are tapered until a desired coupling ratio is achieved. After the insertion loss is measured, the torch is reintroduced into the taper region and one side (e.g., the right side) of the taper region is rotated with a minimal increase in the taper length, i.e., the distance between the two stations is increased only enough to keep an even tension in the taper region.
摘要翻译： 纤维被约束在一起约1厘米。 氧丙烷手电筒用于加热纤维，使其熔合在一起。 同时，纤维夹紧的两个相对移动的平移阶段被拉开，以在纤维中形成双锥形锥形区域。 纤维是渐缩的，直到实现所需的耦合比。 在测量插入损耗之后，将手电筒重新引入锥形区域，锥形区域的一侧（例如，右侧）以锥形长度的最小增加旋转，即两台站之间的距离增加 仅足以在锥形区域保持均匀的张力。
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7.发明授权Optical waveguide sensor arrangement having guided modes-non guided modes grating coupler 失效具有导模的光波导传感器装置 - 非导模光栅耦合器
公开(公告)号：US5641956A
公开(公告)日：1997-06-24
申请号：US595734
申请日：1996-02-02
CPC分类号： G02B6/14 , G01D5/35345 , G01D5/35377 , G02B6/02095 , G02B6/02195
摘要： An optical waveguide sensor arrangement for sensing at least one physical parameter is provided. This arrangement comprises an optical waveguide having guided modes, lossy non-guided modes, and a long period grating coupling the guided modes to the lossy non-guided modes wherein the long period grating produces a wavelength transmission spectrum functionally dependent on the physical parameter sensed. A source means provides light to the optical waveguide sensor and an optoelectronic detector, which is positioned in an operable relationship to the optical waveguide sensor, detects light transmitted through the optical waveguide sensor. Lastly, a processing means is attached to the optoelectronic detector for correlating the wavelength transmission spectrum with a numerical value for the physical parameter sensed. The physical parameters sensed by the optical waveguide sensor include: temperature, strain, shape, refractive index and corrosion.
摘要翻译： 提供了用于感测至少一个物理参数的光波导传感器装置。 这种布置包括具有引导模式，有损非导向模式的光波导和将引导模式耦合到有损非导向模式的长周期光栅，其中长周期光栅在功能上产生取决于所感测的物理参数的波长透射光谱。 源装置向光波导传感器提供光，并且以与光波导传感器可操作的关系定位的光电检测器检测透过光波导传感器的光。 最后，将一个处理装置连接到光电检测器，用于将波长透射光谱与感测物理参数的数值相关联。 由光波导传感器检测的物理参数包括：温度，应变，形状，折射率和腐蚀。
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公开(公告)号：US5208877A
公开(公告)日：1993-05-04
申请号：US751737
申请日：1991-08-29
CPC分类号： G02B6/02047 , G01D5/3538 , G02B6/02123 , G02B6/14
摘要： Two-mode, elliptical-core optic fibers with a permanent photo-induced index change are used as sensors with sensitivity varying as a function of length. The optic fiber sensors act as vibrational-mode filters thereby performing initial signal processing of the sensor signal. The sensors are based on photo-induced refractive index changes. These refractive index changes affect the differential phase modulation between the LP.sub.01 and the LP.sub.11.sup.even modes. The change in beat-length is dependent on the amount of strain induced in the fiber while the grating is being formed. The pattern is thus varied along the length of the fiber by straining the fiber in a specific fashion while the grating is being written. This changes the sensitivity, of the sensor along its length. By choosing an appropriate weighting function in the manufacture of the sensor, it is possible to implement vibrational-mode analysis, vibrational-mode filtering and other functions that are critical in control system applications.
摘要翻译： 使用具有永久光诱导指数变化的双模，椭圆芯光纤作为传感器，灵敏度随长度的变化而变化。 光纤传感器用作振动模式滤波器，从而执行传感器信号的初始信号处理。 传感器基于光诱导的折射率变化。 这些折射率变化影响LP01和LP11模式之间的差分相位调制。 拍子长度的变化取决于在形成光栅时光纤中诱发的应变量。 因此，通过在光栅被写入时以特定的方式使光纤变窄，沿着光纤的长度变化图案。 这会改变传感器沿其长度的灵敏度。 通过在传感器的制造中选择适当的加权函数，可以实现在控制系统应用中至关重要的振动模式分析，振动模式滤波和其他功能。
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公开(公告)号：US5189299A
公开(公告)日：1993-02-23
申请号：US526593
申请日：1990-05-22
IPC分类号： G01L1/24
CPC分类号： G01L1/242
摘要： The present invention pertains to a strain sensor. The strain sensor is comprised of an optical wave guide, a device for providing optical pulses to the optical wave guide and a device for sensing localized strain in the optical waveguide. The sensing device determines shifts in arrival times of the optical pulses at the sensing device that correspond to the localized strain. The apparatus includes a light source, a light detector, and a waveguide connecting the source with the detector. The apparatus also includes means for generating light pulses from the source through the waveguide and means for repeatedly propagating at least one of the light pulses in a closed loop. The light source detects arrival times of the light pulses.
摘要翻译： 本发明涉及应变传感器。 应变传感器包括光波导，用于向光波导提供光脉冲的装置和用于感测光波导中的局部应变的装置。 感测装置确定对应于局部应变的感测装置处的光脉冲的到达时间的移动。 该装置包括光源，光检测器和将源与检测器连接的波导。 该装置还包括用于从源极通过波导产生光脉冲的装置和用于在闭环中重复传播至少一个光脉冲的装置。 光源检测光脉冲的到达时间。
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公开(公告)号：US5446280A
公开(公告)日：1995-08-29
申请号：US114511
申请日：1993-08-31
申请人： Anbo Wang , Kent A. Murphy , Richard O. Claus
发明人： Anbo Wang , Kent A. Murphy , Richard O. Claus
摘要： A fiber optic sensor is fully compensated for light source intensity variation, fiber losses and modal power distribution by providing input to one end of an optical fiber from a relatively broad band light source containing at least two spectrally separated wavelengths. At least one of these spectrally separated wavelengths is reflected back into the optical fiber by a filter located between a second end of the optical fiber and a reflective transducer. The filter is preferably of the interference edge filter type and has a nominal cut-off wavelength within the spectral band of the light source or between the two spectrally separated wavelengths. Therefore, the paths traversed by light of the spectrally separated wavelengths will differ only by twice traversing the reflective transducer. Temperature measurement or compensation can also be provided by sensing of reflected light intensity or power at approximately the nominal cut-off frequency of the filter. Reflective transducers of both the intensity-based and interferometric types are usable with the invention.
摘要翻译： 光纤传感器通过从包含至少两个频谱分离的波长的相对宽带光源提供输入到光纤的一端而完全补偿光源强度变化，光纤损耗和模态功率分布。 这些光谱分离的波长中的至少一个通过位于光纤的第二端和反射换能器之间的滤光器反射回光纤。 滤波器优选地具有干涉边缘滤波器类型，并且在光源的光谱带内或在两个光谱分离的波长之间具有标称截止波长。 因此，通过光谱分离的波长的光穿过的路径将仅通过两次穿过反射换能器而不同。 温度测量或补偿也可以通过在大约过滤器的标称截止频率处感测反射光强度或功率来提供。 基于强度和干涉式的反射换能器可用于本发明。
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