Research On Sensing Technology Based On Tilted Fiber Grating

Fiber Bragg Grating(FBG)is a critical optical passive device,and there are diversified applications in all-optical communication networks,new sensing technology,electronic semiconductors and other industries.The TFBG's grating plane has a certain tilt angle with respect to the fiber axis.This can strengthen the exchange between the grating core mode and the cladding mode or the radiation mode,and TFBG applied in the fields of optical fiber sensing,optical fiber filtering,etc.We mainly studies the characteristics of TFBG and cascaded tilted fiber grating(CTFBG).The specific text is as follows:1.The progress and research status of fiber Bragg gratings are summarized,and the innovative results of the structure,production technology and applications of TFBG research are introduced.And summarized the special structure of cascaded gratings and the frontier development of grating sensing technology.2.Analyzing the coupling equations of the TFBG with the coupling mode theory.The transmission matrix and spectral parameter expressions of the non-uniform grating are deduced by the transmission matrix method.3.For various structural parameters,including the grating inclination angle,grating period,and length,are simulated in detail.The simulation results can generate theoretical guidance for the manufacturing process of grating;Then simulate the temperature in the ambient temperature range of 10?-100?,and observe the change of the central coupling wavelength;For the refractive index characteristics,different refractive index values were set for the grating;Finally,the mutual compensation effect of different structural parameters is combined.4.The principle and analysis method of CTFBG are studied.For the two-stage cascade structure,different structural parameters are analyzed,including tilt angle,cascade phase shift,and cascade relative position,etc.,and the spectral characteristics of the respective cascade TFBG are analyzed;for the temperature of the two-stage and three-stage cascade TFBG Sensing characteristics were simulated,and it was observed that the number of stop bands in the core mode of the transmission spectrum was the same as the number of cascade segments M,the central coupling wavelength shifted to the long wavelength direction,and the temperature sensitivity was improved compared with TFBG.5.Designed a TFBG manufacturing system based on a phase mask,and measured the transmission spectrum of the TFBG interfered by this method;The principle of edge demodulation technology is studied,and the linear edge of TFBG is used to design a dual-sided edge sensor demodulation system.Two-sided dual-channels signal and two-sided four-channels signal demodulation experiments were completed.The sensitivity of temperature sensor are 0.01656 n W/ ?(dual channel)and 0.0087 n W/ ?(four channel).The system can measure temperature value quickly and provide instructions for the practiction of grating sensing technology.