Preparation method of humidity sensitive grating and fiber bragg grating temperature and humidity sensor

Abstract

The invention provides a preparation method of a humidity sensitive grating. The preparation method comprises the following steps: firstly, conducting hydrolysis and impurity removal on plant fibers to obtain a clean solution; conducting desugaring on the clean solution by a certain quantity of ketene or acetic anhydride; then under the action of acid, esterfying a hydroxyl functional group of cellulose to form an acetyl functional group; modifying the surface of the grating by a silane coupling agent so as to change hydroxyl on the surface of the grating into an amido group which is easy to bond with acetyl and comprises silane; cleaning and drying the grating of the amido group comprising silane, placing the grating into the solution of cellulose comprising acetyl to soak so as to form the humidity sensitive grating grafted with cellulose; finally, cleaning and drying the humidity sensitive grating and enabling the plant fibers on the surface of the grating to be connected mutually to form a coating layer. The invention further provides a fiber bragg grating temperature and humidity sensor prepared according to the preparation method of the humidity sensitive grating. The fiber bragg grating temperature and humidity sensor prepared according to the preparation method of the humidity sensitive grating can be simultaneously sensitive to temperature and humidity.

Description

technical field [0001] The invention belongs to the field of intelligent detection, in particular to a method for preparing a moisture-sensitive grating and an optical fiber grating temperature-humidity sensor obtained by the method. Background technique [0002] Fiber Bragg grating is a technology to change the axial refractive index of optical fiber. It can form a grating with a specific period by irradiating the template with ultraviolet light in the case of hydrogen doping and germanium doping in the optical fiber. When the broadband spectrum passes through the optical fiber through the Bragg grating, the full-width spectrum is filtered, the light meeting the wavelength of the Bragg grating is reflected, and the light of other wavelengths passes through the Bragg grating. The essence of a Bragg grating is a narrow-band filter. [0003] When the Bragg grating is deformed by temperature or other effects, the wavelength of the Bragg grating will change, so that the wavelen...

AI Technical Summary

Problems solved by technology

[0004] Existing fiber gratings cannot be used to detect relative humidity and must be sensitized

The existing sensitization technology is to dip the fiber grating into PI (polyacetamide). This method has been proved to be able to sensitize the sensitivity of the grating to humidity, but the performance distribution of the finished product is stray, and the process is affected by the environment.

Images