专利名称：METHOD AND APPARATUS FOR OPTICAL SENSING
column函数的使用方法发明人：FARHADIROUSHAN, Mahmoud,PARKER, Tom,SHATALIN, Sergey感恩戴德
申请号：GB2016/050625
手机广告申请日：20160307阴道炎的原因>桑葚的副作用
公开号：WO2016/142695A1
公开日：思学图书馆官网
20160915
咖啡过敏的症状专利内容由知识产权出版社提供
专利附图：梁思达
摘要：Embodiments of the invention provide an improved optical fiber distributed acoustic nsor system that makes u of a specially designed optical fiber to improve
overall nsitivity of the system, in some embodiments by a factor in excess of 10. This is achieved by inrting into the fiber weak broadband reflectors periodically along the fiber. The reflectors reflect only a small proportion of the light from the DAS incident thereon back along the fiber, typically in the region of 0.001% to 0.1%, but preferably around 0.01% reflectivity per reflector. In addition, to allow for temperate compensation to ensure that the same reflectivity is obtained if the temperature changes, the reflection bandwidth is relatively in the region of +/- 3nm from the nominal lar wavelength. In some embodiments the reflectors are formed from a ries of fiber Bragg gratings, each with a different center reflecting frequency, the reflecting frequencies and bandwidths of the gratings being lected to provide the broadband reflection. In other embodiments a chirped grating may also be ud to provide the same effect. In preferred embodiments, the reflectors are spaced at half the gauge the desired spatial resolution of the optical fiber DAS.
申请人：SILIXA LTD.
地址：WD6 3SN GB
国籍：GB
代理人：WITHERS & ROGERS LLP
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