Distributed stimulated Brillouin temperature strain sensing system based on double-sideband modulation

A technology of stimulated Brillouin and temperature strain, applied in the field of optical fiber, can solve problems such as power gap, power reduction, frequency difference stability, etc.

CN102680136AInactive Publication Date: 2012-09-19BEIJING UNIV OF POSTS & TELECOMM
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2012-09-19
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention provides a distributed stimulated Brillouin temperature strain sensing system based on double-sideband modulation, which includes a narrow linewidth light source, a power divider, a microwave source, a pulse signal emitter, an optical receiver, an optical amplifier, an electrooptical modulator and a sensing optical fiber, wherein a pulse optical signal and a continuous signal that is modulated by double-sideband are input into the two ends of the sensing optical fiber respectively; the pulse optical signal serves as a pumping optical signal; the double-sideband continuous optical signal serves as a detecting optical signal; the pumping optical and detecting optical signals encounter to produce the stimulated Brillouin; and the continuous light carries the temperature or strain information of the points distributed along the sensing optical fiber. The double-sideband technology can effectively controls the Brillouin consumption of the pumping pulse during transmission, and greatly reduces the system error in measurement. The distributed stimulated Brillouin temperature strain sensing system is applicable to the fields as transmission cable and oil-gas pipeline monitoring and fire control, and is particularly applicable to sensing of long distance more than 50km.
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Description

technical field

[0001] The invention belongs to the field of optical fiber technology, and relates to an optical fiber temperature strain sensing system, in particular to a distributed stimulated Brillouin temperature strain sensing method and structure based on double sideband modulation. Background technique

[0002] The distributed optical fiber temperature and stress sensing system based on the stimulated Brillouin effect has the ability to simultaneously obtain the temperature or stress change information of the measured area with time and space, and is suitable for long-distance distributed detection. With its intrinsic explosion-proof, passive and long-distance characteristics, this type of sensor is applied in the fields of oil and gas pipelines, electric power and fire protection, and solves the technical problems that have existed in many industries for many years. It is an important technology in the field of fire protection to monitor and provide precise position...

Examples

Embodiment Construction

[0027] The invention provides a distributed Brillouin temperature strain sensing system based on double sideband modulation. The present invention will be described in detail below in conjunction with the accompanying drawings.

[0028] The present invention provides a distributed Brillouin temperature strain sensing system based on double sideband modulation, such as figure 2 As shown, the system includes a narrow-linewidth light source 201, a microwave source 205, a pulse signal generator 204, an optical amplifier 208, an electro-optic intensity modulator 203, an optical detector 209, and a sensing fiber 212; Continuous light with a frequency of ν0 is divided into two beams through a 50:50 coupler, one of which is modulated by a pulse signal generator and an intensity modulator into a pump light pulse, amplified by an optical amplifier, and injected into the sensing fiber; the microwave source generates a frequency for f m microwave signal, another beam of light is modula...