Extreme environment resistant sapphire fiber bragg grating sensor and temperature detection method thereof

Abstract

The invention discloses an extreme environment resistant sapphire fiber bragg grating sensor and a temperature detection method thereof. In view of the problem of application of a temperature sensor under extreme conditions, the extreme environment resistant sapphire fiber bragg grating sensor comprises: performing fusion splicing on a sapphire crystal fiber with a flat section and a flatly cut single mode fiber, as well as engraving a grating at a single mode near field position on the sapphire crystal fiber close to a fusion splicing point, and coating a protective material at the outside ofthe grated sapphire crystal fiber and the single mode fiber to obtain a sapphire crystal fiber bragg grating temperature sensor; performing mode selection on the light transmitted to a sapphire crystal fiber bragg grating area through the single mode fiber, so that the light of only a few modes or a single mode is transmitted into the sapphire crystal fiber bragg grating area; and when the external temperature changes, the effective refractive index and the grating period of the sapphire crystal fiber bragg grating change, so that the center wavelength changes, and the external temperature change is obtained by demodulation by recording the center wavelength of the sapphire crystal fiber bragg grating.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, in particular to a sapphire crystal fiber grating temperature sensor resistant to extremely severe environments. Background technique [0002] For the measurement of process parameters in extremely harsh environments such as high radiation, high temperature, high pressure, and strong vibration, fiber optic sensors have emerged due to their outstanding advantages, such as natural insulation, not afraid of electromagnetic interference; simple structure, strong environmental tolerance; small size, Good flexibility, suitable for comprehensive layout of ships, can effectively reduce the space occupied by instruments; distributed layout can be used to improve the informatization and intelligence level of the measurement system. Therefore, fiber optic sensors have great potential advantages in the measurement of process parameters in extremely harsh environments. [0003] At present, in t...

AI Technical Summary

Problems solved by technology

[0003] At present, in the nuclear radiation environment, the existing process parameters are measured using traditional electrical sensors, which have defects such as large equipment size and cable volume, weak anti-electromagnetic interference ability, weak accident resistance ability, etc. It is difficult to achieve ideal results in areas related to process parameter measurement

Although some studies have shown the possibility of applying femtosecond-written quartz fiber FBG sensors in nuclear radiation environments, the existing fiber sensor products have not yet formed products that are truly suitable for extremely harsh environments with high radiation, high temperature, high pressure, and strong vibration. Fully meet the needs of safety monitoring in extremely harsh environments

In addition, so far, there is no sapphire single-mode fiber product, and the existing sapphire crystal fiber grating sensors are all fused with multimode fiber and sapphire crystal fiber, and then the writing of the grating on the sapphire crystal fiber is completed.

This technology uses multimode as the transmission fiber to increase the complexity of demodulation

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