Chaotic visible laser-based optical fiber fault positioning device and positioning method thereof

[0024] Example 2

[0025] Implementation of the present invention is a method for locating the optical fiber fault locating device based on chaotic visible laser in embodiment 1: the chaotic visible light signal is divided into the detection signal I and the reference signal II through the optical fiber coupler 2, and the reference signal is reflected by the optical fiber fault point 11. The latter echo signal enters the signal processing device 9 for cross-correlation processing. The principle of cross-correlation processing to measure the propagation time of light in the optical fiber is: suppose that the chaotic laser generated by the chaotic visible laser generator conforms to the characteristics of the non-periodic function f(t) , The chaotic light I and the chaotic light II divided by the fiber coupler conform to the characteristics of the functions k*f(t) and (1-k)f(t) respectively. The chaotic light I as the probe light is reflected by the fiber fault point The light satisfies the function relation k*f(t-τ 0 ), when the two signals are processed separately to obtain a digital signal and enter the signal processing device 9, the mathematical expression for cross-correlation processing is: F ( τ ) = ∫ - ∞ + ∞ k ( 1 - k ) f ( t - τ ) f ( t - τ 0 ) dt , When τ=τ 0 When the function has a peak value, the propagation time t of the light in the fiber to be tested is obtained, and the distance of the light propagating in the fiber to be tested is calculated by the formula L=V*t/2, that is, the length of the fiber between the fault point 11 and the detection point L , So as to obtain the maximum distance range of the optical fiber failure point, and output through the display 10. Reusing the visible characteristics of the chaotic visible laser will produce obvious visible bright spots due to transmission at the fault point 11, which is the actual location of the fault point, so only the visible bright spot needs to be found within the maximum distance of the fiber fault point. Achieve accurate positioning of the point of failure. Combining chaos-related fault point detection technology and visible light fiber fault point detection technology, firstly realize a rough measurement of the location range of the fiber fault point, and then complete the accurate location of the fiber fault point within the measurement range to realize the fiber fault point Fast and accurate positioning of the location.