Measuring system for detecting OTDR by using symmetrical linear chirped pulses

Abstract

The invention relates to a measuring system for detecting OTDR by using symmetrical linear chirped pulses. The system can detect microsecond-level temperature or change trend of stress acting on an optical fiber to be detected in a distributed optical fiber sensor system by using the symmetrical linear chirped pulses as detection light; by utilizing the characteristics of electromagnetic resistance, corrosion resistance and high temperature resistance of the optical fiber, the system can be used in a high-risk environment for detection operation; linear chirped pulses are used as detection light and are symmetrical pulse light in a frequency band range, and at an acting point of the to-be-measured optical fiber, backward Rayleigh scattering is used, and two detection wave crests are reflected back; a microsecond-level time difference exists between the two wave crests, so that the two wave crests reflect different disturbances; and the change trend of the to-be-measured physical quantity measured between the two wave crests, namely in the microsecond order of magnitude, is extracted through modulation and demodulation of the two waves, and the defects that a traditional distributedoptical fiber sensor needs to sweep frequency continuously, can only measure the dependent variable and needs long time are overcome.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensors, in particular to a measurement system for symmetrical linear chirped pulse detection OTDR. Background technique [0002] The traditional distributed optical fiber sensor has the disadvantage of mutual restriction between spatial resolution and dynamic range in the positioning of the event point of the optical fiber to be tested, resulting in the sacrifice of another performance when improving one performance index, and only the coordinates of the event point can be measured However, it is unable to detect the trend of disturbance changes. These shortcomings restrict the development of optical fiber sensors in the field of detecting high-precision temperature and stress changes. Contents of the invention [0003] In order to overcome the deficiencies of the prior art above, the present invention provides a measurement system for symmetric linear chirped pulse detection OTDR. [00...

AI Technical Summary

Problems solved by technology

[0002] The traditional distributed optical fiber sensor has the disadvantage of mutual restriction between spatial resolution and dynamic range in the positioning of the event point of the optical fiber to be tested, resulting in the sacrifice of another performance when improving one performance index, and only the coordinates of the event point can be measured However, it is unable to detect the trend of disturbance changes. These shortcomings restrict the development of optical fiber sensors in the field of detecting high-precision temperature and stress changes.

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