Array waveguide grating-based temperature sensing method and temperature sensor

Abstract

The invention belongs to the technical field of temperature measurement and discloses an array waveguide grating-based temperature sensor. A single wave-length laser is input into an array waveguide grating which serves as a temperature sensing and detecting element and is provided with at least two output passages, and the ambient temperature value of the array waveguide grating is obtained by monitoring the light intensities of the two output passages of the array waveguide grating, so that the aim of sensing temperature is fulfilled. The invention also provides a temperature sensing method implemented by using the sensor. Compared with other fiber optic sensors, the sensor is affected by the power fluctuation or frequency departure of a laser and has higher accuracy. The method and the sensor can be used for monitoring and controlling temperature or preventing fire in various environments with high electromagnetic interference and the like.

Description

technical field [0001] The invention belongs to the technical field of temperature measurement, and in particular relates to a temperature sensor based on an arrayed waveguide grating. Background technique [0002] In a variety of strong electromagnetic environments, in some areas where current cannot exist, or under conditions that require long-distance temperature sensing: such as temperature monitoring in power plants, substations, oil depots, and forest fire monitoring, etc., based on optical temperature sensing The advanced sensor is widely used for its anti-electromagnetic interference, no current passing through the sensing element, and low signal loss in long-distance transmission. [0003] At present, the temperature sensor based on fiber grating is widely used. The sensing principle is that the central wavelength of the reflection spectrum of the fiber grating changes with the change of the ambient temperature. The temperature information is obtained through analy...

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Problems solved by technology

[0003] At present, the temperature sensor based on fiber grating is widely used. The sensing principle is that the central wavelength of the reflection spectrum of the fiber grating changes with the change of the ambient temperature. Analyze and obtain temperature information. The disadvantage of this method is that the cost of temperature sensor controller is relatively high.

U.S. Patent 6024488 discloses a temperature sensor based on dual fiber gratings. Its principle is to simultaneously calculate the laser wavelength and the ambient temperature by analyzing the reflection spectra of two gratings whose spectra vary with the ambient temperature. The disadvantage of this method is that the laser Power changes will affect the temperature sensing accuracy, and it is necessary to process two kinds of fiber gratings with different thermo-optic coefficients, and to accurately calculate or test the reflection spectrum of fiber gratings, so the production cost is high

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