A dynamic pressure detection system and method based on fiber grating Stokes parameters

Abstract

The invention discloses a dynamic pressure detection system and a method based on fiber grating Stokes parameters. The system comprises a tunable laser, an electric polarization controller, a sensing fiber grating, a polarization detection module, a signal processing module, a feedback module and a display unit, wherein the tunable laser emits laser of a certain wavelength and feeds the laser to the electric polarization controller and to the sensing fiber grating; the online polarization detection module acquires laser transmitted from the sensing fiber grating, the laser is outputted to the signal processing module, and three Stokes parameters for the polarization state of the transmitted laser are obtained; and the signal processing module feeds back the parameters to the electric polarization controller to adjust the polarization state of incident laser. Linear birefringence is generated by the fiber grating under effects of external pressure, three parameters for the transmitted laser are caused to change, a single-wavelength source is adopted to realize real-time sensing on the size of the dynamic pressure, the defect that the traditional method is not suitable for small pressure sensing can be overcome, and the defect that the sensing method based on the grating polarization parameter maximum value is not suitable for dynamic pressure sensing can be solved.

Description

technical field

[0001] The invention relates to the technical field of optical fiber sensing, in particular to an optical fiber sensing device for real-time monitoring of pressure by using the Stokes parameter of the transmitted light of an optical fiber grating. Background technique

[0002] When the optical fiber is affected by the external environment (temperature, stress, magnetic field, pressure, etc.), the parameters such as the intensity, phase, frequency, and polarization state of the transmitted light in the optical fiber will change accordingly. By detecting these parameters of the transmitted light, the change of the corresponding physical quantity can be known. This technology is called fiber optic sensing technology.

[0003] As a mature all-fiber device, fiber grating has very important applications in the fields of optical fiber communication and optical fiber sensing due to its small size, low insertion loss, and easy integration with other optical fiber devi...

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