The Study On Temperature Sensitivity Of Photonic Crystal

In recent years, photonic crystal has been widespread concern in the field of Nano-sensor technology. People continue to carry out exploration and research, and look forwardthat photonic crystal can create a new space for the development of Nano-sensor technology.This paper mainly study of the research about photonic crystal temperature sensor, includingtwo aspect as follow:1.Making the photonic crystal temperature sensor working in a particular wave band asthe research object. Firstly, the transfer matrix method is used to calculated the transmissivityof the defect mode of the one-dimension photonic crystal with mirror structure thetransmission spectrum of the photonic crystal was simulated by mathematical softwareMatlab, and there is a transmission peak whose value is1in the photonic bandgap. When thetemperature is changed, the value of transmission peak of photonic crystal do not change, atthe same time the transmission peak and the photonic band gap drift based on the thermalexpansion effect and thermo-optic effect of photonic crystal. And there is a certain rulebetween them. The drift of the center wavelength of the transmission peak or the startingwavelength of the photonic bandgap with the change of temperature was fitted by the drawingsoftware Origin. It is found that there is a simple linear relationship between the rise oftemperature and the center wavelength or the starting wavelength. And then the sensitivity ofthe photonic crystal to the temperature can be calculated by getting the value from the fitting.Then the influence of the media layer thickness of the photonic crystal on the sensitivity ofthe photonic crystal temperature sensor was analyzed. After introducing the thickness ofmedia layer, the value of the transmission peak of photonic crystal and the sensitivity of thephotonic crystal temperature sensor remain the same, but the center wavelength of thetransmission peak and the wave band where the photonic band gap is are affected by thethickness error. So the working wave band of the photonic crystal is affected. 2. The transfer matrix method is used to calculated the transmissivity of the defectmode of the photonic crystal with defect layer. The transmission spectrum of the photoniccrystal was simulated by mathematical software Matlab, The research object is the defectmode at the wavelength800nm. And it is founded that: when the temperature is changed,firstly, the value of the transmission peak of the photonic crystal decreases with the increaseof temperature. It is proved that the transmission peak of the photonic crystal is sensitive tothe change of temperature. Secondly, in view of the dielectric material of photonic crystalscan not be completely transparent, so there is absorption effect in the dielectric material, therefractive index of the medium is replaced by the complex refractive index. Introducing theabsorption effect of material can slow down the speed of change of transmission peak of thephotonic crystal with the change of temperature, and make the sensitivity that photonic crystalchange with temperature decrease. Finally, the greater the extinction coefficient of thematerial of the photonic crystal, the smaller the sensitivity of defect mode of the photoniccrystal to the change of temperature.