Frequency multiplexing and demultiplexing multichannel grating demodulation device and method

A frequency multiplexing and grating demodulation technology, applied in the direction of using optical devices, measuring devices, thermometers with physical/chemical changes, etc. Advanced problems, to achieve the effect of cost reduction, cost saving, and improvement of demodulation rate

CN114383527AInactive Publication Date: 2022-04-22武汉奇测科技有限公司
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2022-04-22
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a frequency multiplexing and demultiplexing multichannel grating demodulation device and method. The sensing device comprises a linear sweep frequency laser, a first optical fiber coupler, a second optical fiber coupler, an optical fiber circulator, an optical fiber beam splitter, a plurality of acousto-optic frequency shifters, an FBG (Fiber Bragg Grating), a photoelectric detector, a data acquisition card and a computer. Based on a coherent detection technology, multi-channel signals are subjected to frequency multiplexing, photoelectric signal conversion is realized in a single photoelectric detector, a single-channel acquisition card is used for analog-to-digital conversion, an FPGA in the acquisition card is used for realizing FFT operation, and a physical position and a spectral signal of a to-be-detected FBG are output. And finally, performing a series of data processing operations such as window inverse Fourier transform and the like in calculation to obtain temperature and strain fast demodulation. According to the invention, multi-channel fast fiber grating demodulation can be realized, sweep-frequency light source multiplexing and single-channel acquisition are realized, and the cost of the demodulation device is greatly saved on the premise of meeting the performance.
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Description

technical field

[0001] The invention relates to the technical field of optical fiber sensing, in particular to a multi-channel grating demodulation device and method for frequency multiplexing and demultiplexing. Background technique

[0002] High-speed strain measurement, impact and vibration testing have a wide range of requirements. Conventional means include electronic strain gauges and fiber gratings; electronic strain gauges are not suitable for special fields due to electrical and electromagnetic compatibility problems. Fiber Bragg grating strain measurement has the characteristics of small size, light weight, high sensitivity, strong anti-interference ability, etc., and is especially suitable for monitoring high-speed strain, impact and collision.

[0003] At present, fiber optic sensing demodulation technology is developing rapidly, among which FBG (Fiber Bragg Grating, Fiber Bragg Grating) demodulation based on tunable laser light source has attracted more attenti...

Examples

Embodiment Construction

[0032] In order to make the technical means, creative features, goals and effects achieved by the present invention easy to understand, the present invention will be further elaborated below in conjunction with specific embodiments and accompanying drawings, but the following embodiments are only preferred embodiments of the present invention, not all . Based on the examples in the implementation manners, other examples obtained by those skilled in the art without making creative efforts all belong to the protection scope of the present invention.

[0033] Specific embodiments of the present invention will be described below in conjunction with the accompanying drawings.

[0034] An embodiment of the present invention is a frequency multiplexing and demultiplexing multi-channel grating demodulation device, which uses a total of 2 channels, including a linear frequency sweep laser 1, a first fiber coupler 2, a fiber circulator 3, and a second fiber coupling 4, fiber beam split...