A temperature sensing method and temperature sensor based on arrayed waveguide grating

Abstract

The invention belongs to the technical field of temperature measurement, and discloses a temperature sensor based on an arrayed waveguide grating. In the invention, a single-wavelength laser is input to an arrayed waveguide grating with at least two output channels as a temperature sensing element, and the The light intensity of the two output channels of the arrayed waveguide grating is monitored to obtain the temperature value of its environment, so as to realize the purpose of temperature sensing. The present invention also provides a temperature sensing method realized by using the above sensor. Compared with other optical fiber sensors, the present invention is not affected by laser power fluctuation or frequency drift, and has relatively high precision. The invention can be used for temperature monitoring, monitoring or fire prevention in various environments such as strong electromagnetic interference.

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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