Polarization maintaining optical fiber extinction-ratio self-adaptive demodulation method

A technology of polarization-maintaining fiber and demodulation method, which is applied in the field of optical measurement, and can solve the problems of complex experimental equipment, difficult implementation, and theoretical test accuracy limited to 60dB.

CN102706538AInactive Publication Date: 2012-10-03TIANJIN UNIV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2012-10-03
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to a polarization maintaining optical fiber extinction-ratio self-adaptive demodulation method, which solves the polarization maintaining optical fiber extinction-ratio data demodulation problem. The polarization maintaining optical fiber extinction-ratio self-adaptive demodulation method comprises self-adaptive extinction-ratio threshold value coupling strength and converged non-uniform extinction-ratio iteration step. The demodulation comprises the steps of dynamically setting the extinction-ratio threshold value coupling strength according to the coupling situation inside an optical fiber to be measured, and realizing the self adaptability of the demodulation method; ensuring the iteration step to be dynamically changed and non-uniformly converged because the extinction-ratio iteration step depends on the previous iteration result and the iteration times, and realizing the quick demodulation of the polarization maintaining optical fiber extinction ratio; and detecting a weak coupled point inside the polarization maintaining optical fiber by adequately utilizing the characteristic that the white light interference precision is high and the dynamic range is large, and ensuring the demodulation result to be more precise and more reliable through the data preprocessing and self-adaptive extinction-ratio demodulation method.
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Description

technical field

[0001] The invention relates to the detection of distributed polarization coupling of polarization-maintaining optical fiber by white light interferometry, in particular to an adaptive demodulation method for extinction ratio of polarization-maintaining optical fiber based on distributed polarization coupling, and belongs to the technical field of optical measurement. Background technique

[0002] High birefringence polarization-maintaining fiber is widely used in fiber optic gyroscope, fiber optic sensing, integrated optical information processing, optical communication, etc. and other fields. Extinction ratio is an important index to measure the polarization state stability performance of polarization maintaining fiber. Due to the influence of various internal and external disturbances such as internal stress defects, transverse stress, bending, twisting and other factors in the polarization maintaining fiber, its polarization extinction ratio is often low...

Examples

Embodiment 1

[0045] Connect the Nufern polarization-maintaining optical fiber with a center wavelength of 850nm and a length of 3m to the test system. After starting all the equipment, collect white light interference data. Figure 5 (a) shows the original interferometric data collected when the light source power is 8mW. Calculate the coupling strength from the collected raw interferometric data, and get Figure 5 (b) Coupling strength data shown. The coupling strength at the fiber connection is relatively high, so the data points representing the coupling strength of the polarization-maintaining fiber to be tested are located. The coupling strength data points of the fiber to be tested are shown in the figure. Coupling strength data points for polarizer pigtails. First take out the maximum value of these coupling strength data points, and calculate the extinction ratio threshold coupling strength according to this value; take out the coupling strength data points greater than the thres...

Embodiment 2

[0049] The central wavelength is 850nm, and the polarization maintaining optical fiber with a length of 12m is connected to the test system for white light interference data collection. The coupling strength is calculated from the collected original interference data, and the coupling strength data of the 12m optical fiber to be tested is obtained. According to the high coupling strength at the fiber connection, locate the coupling strength data point representing the polarization-maintaining fiber to be tested. Coupling strength data points for polarizer pigtails. First take out the maximum value of these coupling strength data points, and calculate the extinction ratio threshold coupling strength according to this value; take out the coupling strength data points greater than the threshold coupling strength to calculate the extinction ratio; recalculate the extinction ratio threshold coupling strength according to the newly obtained extinction ratio, Cycle in turn until the...