Laser light emitted by the fiber-coupled to a 2x2 single-mode fiber coupler, the coupler incident light is divided into clockwise and counterclockwise propagation, and P, P 'two o'clock by the interference of external stress (percussion) the two beam interference formation in the surface of the PD detector. 


 Daily increase in current demand for fiber optic cable, optical cable from the previous single-core expansion to a maximum of 2096 core, but the fiber optic cable laying, the more, the problems brought about the greater. Communications integration of rapid development, electricity, broadcasting and other cutting-edge strength, the merger of the operator's need to maintain resulting in a large number of fiber optic cable, so how to correctly distinguish between the fiber optic cable has become an urgent need to solve the problem. 
 The handheld device is compact and lightweight, easy to operate 
 Field applications to meet the demand for telecommunications users 
 Dozens of kilometers long-range mechanical vibrations of the sensor cable, fiber optic cable in a complex environment through audio or visual signals to target 
 Automatically optimize the device parameters for lines of different lengths 
 Test non-destructive testing to identify high accuracy.