High Sensitivity ?-Pressure Sensor Considering The Effects Of Temperature

Sensors play an important role in production and living.Photonic crystal based sensors have been widely used in recent years because of low loss,small size,light weight and high sensitivity.Photonic band gaps and optical locality are the basis of sensing functions.While many types of transmission are transmitted.The pressure sensor uses the local characteristic of point defect and the line defect in the photonic crystal.Under the action of the external pressure stress,the pressure sensor is realized by the linear variation of the local mode.On the basis of the original work,considering the influence of the actual environmental temperature on the measurement,a high sensitivity u-pressure sensor considering the effects of temperature is designed.In this thesis,point defect and line defect are introduced into the photonic crystal in order to get a narrow-band filter.The design of the structure and the optical characteristic are simulated by COMSOL Multiphysics 5.0.It is used to analyze the bandgap of the photonic crystal.The pressure and temperature are introduced at the same time analyze the transmission spectrum.An obvious red-shift linear relationship can be observed between resonant wavelength with pressure and temperature.Above all a u-pressure sensor based on photonic crystals considering temperature influence is proposed.The main work of this thesis is divided into the following aspects:Firstly,the optical properties of perfect photonic crystals are introduced,at the same time the effects of various structural parameters such as(a,r,k,n)on optical properties are inclued.Choose materials for silicon photonic crystal structure,lattice constant is 600 nm,the radius of the rods is 0.15a.Photonic crystal band gap range in 0.33--0.48(a/?),which is 1250-1818 nm.In a perfect introduction of point defects and line defects in photonic crystal structure constitute a narrow-band filter.In this paper,the cantilever structure is designed and the pressure stress of the filter is applied to the filter through the cantilever structure.The simulation results show that the filter mode has a linear movement under the influence of the pressure stress,so the u-pressure sensor is designed.In order to improve the sensitivity of the sensor,the micro cavity part is optimized,and its pressure sensitivity can be improved to0.728nm/?N.While in the actual measurement,the sensitivity may be affected by the external environment under different temperature.Considering the influence of temperature,the pressure sensor of the dual channel is designed.Fist,considering the line structure of the photonic crystal wavelength-pressure sensor.Cavity A and cavity B coupling field distribution of different input frequency.Cavity model corresponding to the wavelength is ?_?=1699nm,?_b = 1452nm respectively.The temperature sensitivity coefficient of two output ports are optimized to k_? = 0.1053nm/?,kb = 0.0824nm/?.The pressure sensitivity is up to 0.802nm/?N.The structure of band rejection filter.Cavity A and cavity B coupling field distribution of different input frequency.Cavity model corresponding to the wavelength is ?_? = 1699nm,?_b= 1452nm respectively.The temperature sensitivity coefficient of two output ports are optimized to k_? = 0.1277nm/?/,kb= 0.0973nm/?.The pressure sensitivity is up to 1.33nm/?N.Another kind of structure:structure of narrow-band filter.Design the different pattern on the inside of two waveguide cavity A and Cavity B model corresponding to the wavelength is ?_? = 1626nm,?_b = 1473nm respectively.Through continuous optimization,the temperature sensitivity coefficient of the two output port is up to k_? = 0.1295nm/?,?_b= 0.0912nm/?.The pressure sensitivity is up to 1.427nm/?N.