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美国洛斯阿拉莫斯国家实验室的地球物理学家把一对插入地孔中的光纤粘接起来,希望能探测地球应力从而给出地震的早期预报。这种光纤传感器比起迄今所知的任何一种可比的地震传感器来灵敏度要高得多,而且设计简单,成本低廉。这种应力传感器靠探测在应变和未应变光纤中光传输的差别。一条传感光纤粘贴在岩石上;第二条平行光纤与岩石脱离,因而它不受应力。加应力于光纤即可改变其传输光线的路径。根据应变的程度,受应力光纤中的光比脱离岩石的光纤中的光传得更远些。当从两条光纤来的光束再会合时,它们
Geophysicists at Los Alamos National Laboratory in the United States bonded a pair of optical fibers inserted into a hole in the hope of detecting Earth’s stress and giving an early prediction of the earthquake. This type of fiber optic sensor is much more sensitive than any of the comparable seismic sensors known to date and is simple to design and cost effective. This stress sensor by detecting the optical fiber in the strain and unstrained optical transmission difference. A sensing fiber is attached to the rock; the second parallel fiber is detached from the rock so it is not stressed. Plus stress on the fiber to change the path of light transmission. Depending on the degree of strain, the light in the stressed optical fiber travels farther than the light in the rock-free fiber. When the beams from two fibers rejoin them