Blazed fiber bragg grating demodulation-based micro-displacement sensor and detection method

Abstract

The invention relates to a blazed fiber bragg gating demodulation-based micro-displacement sensor and a detection method and belongs to the technical field of photoelectric detection. The sensor consists of a wideband light source 1, an optical circulator 2, optical fiber links (31, 32, 33), fiber bragg gating 4 used for sensing, a double-arched beam 5, a base 6, a helix millesimal screw 7, a blazed fiber bragg gating 8 used for demodulation, a refractive index matching liquid groove 9, a columnar lens 10, an optical fiber array 11, a CCD photoelectricity prober 12, a signal processing unit 13 and a computer 14. The sensor is characterized in that a reflective spectrum signal of the fiber bragg gating 4 used for sensing is broadened under the action of the detected micro-displacement; the signal is sent to the optical fiber array 11 by the blazed fiber bragg gating 8 used for demodulation with a certain beam angle and is transmitted to the CCD photoelectricity prober 12; the error of the measurement caused by light intensity wave, optical fiber transmission loss and the like is avoided on the basis of a gauss fitting algorithm and by identifying the detected displacement corresponding to the facula size received by the CCD photoelectricity prober 12.

Description

technical field [0001] The invention relates to a micro-displacement sensor and a detection method based on blazed fiber grating demodulation, and belongs to the technical field of photoelectric detection. Background technique [0002] At present, the existing optical fiber grating displacement detection systems mostly use piezoelectric ceramic displacement drivers to deform piezoelectric ceramics under the action of electrical signals, so that the reflection wavelength signal of the fiber grating sensor pasted on it moves. The amount of wavelength shift enables the measurement of displacement. Or use some smart structures to convert the displacement into the strain of the fiber grating, and generally the fiber grating is subjected to equal strain, so that the reflection wavelength of the fiber grating sensor moves. However, most of the technologies and methods for detecting the shifting amount of the reflected wavelength of the fiber grating sensor are large and complex, a...

AI Technical Summary

Problems solved by technology

Because there are moving parts in the detection process of this method, piezoelectric ceramics have a hysteresis phenomenon, so the stability of the system is not high, and the cost of this method is relatively high, generally more than 100,000 yuan

[0003] In addition, due to the cross-sensitivity of strain and temperature of fiber grating itself, the sensor design and signal demodulation method based on fiber grating either cannot realize the separate detection of strain signal and temperature signal, or need to add special structures and components , combined with a special algorithm to achieve the separate detection of strain and temperature, in order to solve the problem of cross-sensitivity of fiber grating sensors

Images