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公开(公告)号：US09243949B2
公开(公告)日：2016-01-26
申请号：US13979262
申请日：2012-01-16
摘要： This application describes methods and apparatus for fiber optic distributed acoustic sensing (DAS) where microstructured fiber (202), such as holey fiber or photonic crystal fiber is used as the sensing fiber (104). The microstructured fiber is configured so to provide at least one of enhanced sensitivity to a given incident acoustic signal; an enhanced non-linear optical power threshold and directional sensitivity. By configuring the microstructured fiber to be more compliant than an equivalent solid fiber and/or provide a large refractive index variation in response to applied strain, the response to a given acoustic stimulus may be larger than for the equivalent fiber, Providing a hollow core may allow higher optical powers and by providing a directionality to microstructured (304) allows the fiber to be used in a DAS system with a directional response.
摘要翻译： 本申请描述了用于光纤分布式声学感测（DAS）的方法和装置，其中使用诸如多孔光纤或光子晶体光纤的微结构纤维（202）作为感测光纤（104）。 微结构纤维被配置为提供对给定入射声信号的增强灵敏度中的至少一个; 增强的非线性光功率阈值和方向灵敏度。 通过将微结构纤维配置为比等效的固体纤维更柔顺，和/或响应于应变应变提供大的折射率变化，对给定声学刺激的响应可能大于等效纤维的响应。提供中空芯可以 允许更高的光功率并且通过向微结构化提供方向性（304）允许光纤在具有定向响应的DAS系统中使用。
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公开(公告)号：US20130291642A1
公开(公告)日：2013-11-07
申请号：US13979262
申请日：2012-01-16
IPC分类号： G01H9/00
摘要： This application describes methods and apparatus for fibre optic distributed acoustic sensing (DAS) where microstructured fibre (202), such as holey fibre or photonic crystal fibre is used as the sensing fibre (104). The microstructured fibre is configured so to provide at least one of enhanced sensitivity to a given incident acoustic signal; an enhanced non-linear optical power threshold and directional sensitivity. By configuring the microstructured fibre to be more compliant than an equivalent solid fibre and/or provide a large refractive index variation in response to applied strain, the response to a given acoustic stimulus may be larger than for the equivalent fibre, Providing a hollow core may allow higher optical powers and by providing a directionality to microstructured (304) allows the fibre to be used in a DAS system with a directional response.
摘要翻译： 本申请描述了用于光纤分布式声学感测（DAS）的方法和装置，其中使用诸如多孔光纤或光子晶体光纤的微结构纤维（202）作为感测光纤（104）。 微结构纤维被配置为提供对给定入射声信号的增强灵敏度中的至少一个; 增强的非线性光功率阈值和方向灵敏度。 通过将微结构纤维配置为比等效的固体纤维更柔顺，和/或响应于应变应变提供大的折射率变化，对给定声学刺激的响应可能大于等效纤维的响应。提供中空芯可以 允许更高的光功率并且通过向微结构化提供方向性（304）允许光纤在具有定向响应的DAS系统中使用。
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公开(公告)号：US09599489B2
公开(公告)日：2017-03-21
申请号：US12282784
申请日：2007-03-08
CPC分类号： G01D5/35383 , G01D5/35303
摘要： A fiber-optic sensor array (100) comprises a line array of fiber-optic sensor packages (AX, BX, CX, DX, AY, BY, CY, DY, AZ, BZ, CZ, DZ) each having a package input/output (i/o) fiber and each being arranged to output a finite output pulse series of optical output pulses via the package i/o fiber in response to input thereto of one or more interrogating optical pulses. The array further comprises a fiber-optic bus (104,106, 108, 110) extending along the length of the line array, each package i/o fiber being optically coupled to the fiber-optic bus at a respective positions along the line array. The array allows interrogation at a higher frequency than is the case for a serial array of the same number of fiber-optic sensing packages.
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公开(公告)号：US08079261B2
公开(公告)日：2011-12-20
申请号：US10586105
申请日：2005-01-12
IPC分类号： G01P15/13
CPC分类号： G01H9/004 , G01P15/093 , G01V1/181 , G02F1/0134
摘要： A fibre optic accelerometer particularly intended for use with an interferometer using the compliant cylinder approach but further providing a seismic mass at the core of the cylinder resulting in improved sensitivity and rejection of out-of-axis inputs.
摘要翻译： 特别是与干涉仪一起使用的光纤加速度计，其使用柔性气缸方式，但进一步在气缸的核心处提供地震质量，从而提高了轴外输入的灵敏度和排除。
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公开(公告)号：US20110096623A1
公开(公告)日：2011-04-28
申请号：US12999115
申请日：2009-06-15
CPC分类号： G01V1/24
摘要： A method of sensing using a phase based transducer in which a transducer response is provided at multiple different levels of sensitivity. The different levels of sensitivity are used to produce an output which does not overscale across a wide range of signal levels. This is particularly useful for use in conjunction with multiplexed arrays of fibre optic sensors for seismic surveying. Methods of sensor calibration and noise reduction are also described.
摘要翻译： 一种使用基于相位的传感器进行感测的方法，其中在多个不同灵敏度级别提供换能器响应。 使用不同的灵敏度水平来产生在宽范围的信号电平上不超标的输出。 这对于与用于地震测量的光纤传感器的复用阵列结合使用特别有用。 还描述了传感器校准和降噪的方法。
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公开(公告)号：US08248589B2
公开(公告)日：2012-08-21
申请号：US12666897
申请日：2008-07-04
IPC分类号： G01N21/00
CPC分类号： G01D5/247
摘要： A method of interrogating a phase based transducer by providing a pulsed input including two different wavelengths in which the different wavelength components can be used to derive a phase change experienced by a synthetic wavelength, and by arranging for the synthetic wavelength to be significantly greater that the component wavelengths, the phase so detected has a reduced sensitivity, and is less susceptible to overscaling effects.
摘要翻译： 一种通过提供包括两种不同波长的脉冲输入来询问基于相位的换能器的方法，其中不同波长分量可用于导出由合成波长所经历的相位变化，并且通过将合成波长设置为明显大于 分量波长，所以如此检测的相位具有降低的灵敏度，并且不太容易发生超标效应。
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公开(公告)号：US20120188533A1
公开(公告)日：2012-07-26
申请号：US13499076
申请日：2010-09-24
IPC分类号： G01N21/49
CPC分类号： G01D5/35303 , G01H9/004
摘要： A method of distributed acoustic sensing (DAS) whereby the derivative or rate of change of a signal backscatted from a fibre is measured. The change, or derivative of the phase measured in this way has a much smaller amplitude than the signal itself if the difference between the two times at which the signal is measured is much less than the period of the signal being measured, resulting in lower sensitivity. Frequency shifts can be applied to temporally displaced return signals to compare the rate of change, for example by employing an output interferometer arranged to modulate the signal in each arm by a different frequency shift.
摘要翻译： 一种分布式声学感测（DAS）的方法，其中测量从光纤反向扫描的信号的微分或变化率。 以这种方式测量的相位的变化或导数比信号本身的幅度小得多，如果测量信号的两次之间的差异远小于被测信号的周期，导致较低的灵敏度 。 频移可以应用于时间上移位的返回信号以比较变化率，例如通过采用布置成通过不同频移调制每个臂中的信号的输出干涉仪。
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公开(公告)号：US20100067018A1
公开(公告)日：2010-03-18
申请号：US12529291
申请日：2008-03-10
CPC分类号： G01D5/35303 , G01D5/35383 , G01H9/004
摘要： Interrogation of a phase based transducer is performed by comparing the state of the transducer at two points in time to determine the rate of change with time of the measurand represented as a phase change. The rate of change, or derivative of the phase change typically has a much smaller amplitude than the signal itself, and the derivative measurement can therefore be thought of as a low sensitivity measurement to be used instead of or in combination with the normal signal measurement having higher sensitivity. In this way, large amplitude signals which might otherwise be subject to overscaling effects can be measured more effectively. For a signal with the majority of its energy centred at approximately 800 Hz, for example, the derivative of that signal will typically be attenuated by 60 dB with a period between the two measurement times of 200 ns.
摘要翻译： 基于相位的换能器的询问是通过比较两个时间点上的换能器的状态来确定被测量的随时间变化的速率作为相位变化来执行的。 变化率或相位变化的导数通常具有比信号本身小得多的幅度，因此，导数测量可以被认为是低灵敏度测量，以代替或与正常信号测量结合使用，具有 灵敏度更高。 以这种方式，可以更有效地测量否则可能会产生超大效应的大振幅信号。 对于其大部分能量集中在大约800Hz的信号，例如，该信号的导数通常将在200ns的两个测量时间之间的周期内衰减60dB。
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公开(公告)号：US20090080828A1
公开(公告)日：2009-03-26
申请号：US12282784
申请日：2007-03-08
IPC分类号： G02B6/00
CPC分类号： G01D5/35383 , G01D5/35303
摘要： A fibre-optic sensor array (100) comprises a line array of fibre-optic sensor packages (AX, BX, CX, DX, AY, BY, CY, DY, AZ, BZ, CZ, DZ) each having a package input/output (i/o) fibre and each being arranged to output a finite output pulse series of optical output pulses via the package i/o fibre in response to input thereto of one or more interrogating optical pulses. The array further comprises a fibre-optic bus (104,106, 108, 110) extending along the length of the line array, each package i/o fibre being optically coupled to the fibre-optic bus at a respective positions along the line array. The array allows interrogation at a higher frequency than is the case for a serial array of the same number of fibre-optic sensing packages.
摘要翻译： 光纤传感器阵列（100）包括光纤传感器封装（AX，BX，CX，DX，AY，BY，CY，DY，AZ，BZ，CZ，DZ）的线阵列， 输出（i / o）光纤，并且每个光纤布置成响应于一个或多个询问光脉冲的输入，经由封装i / o光纤输出有限的输出脉冲序列的光输出脉冲。 阵列还包括沿着线阵列的长度延伸的光纤总线（104,106,108,110），每个封装i / o光纤在沿着线阵列的相应位置处光耦合到光纤总线。 该阵列允许以比相同数量的光纤传感封装的串行阵列的情况更高的频率进行询问。
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公开(公告)号：US09677956B2
公开(公告)日：2017-06-13
申请号：US13509425
申请日：2010-11-11
IPC分类号： G02B6/02 , G01N9/00 , G01N21/47 , G01L1/24 , G01D5/353 , G01H9/00 , G01L11/02 , G02B6/44 , G02B6/032
CPC分类号： G01L1/243 , G01D5/3538 , G01H9/004 , G01L11/025 , G01V1/208 , G01V1/52 , G02B6/02 , G02B6/443 , G02B2006/0325
摘要： Fiber optic cables with improved performance for use in distributed sensing, for instance in distributed acoustic sensors, are disclosed. In one embodiment a fiber optic cable (210) comprises a core (208) and cladding (206) disposed within a buffer material (202) and surrounded by a jacket (204) and arranged so that the core is offset from the center of the cable. By offsetting the core from the center of the jacket any bending effects on the core can be maximised compared with the core being located at the center of the cable.
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