Research On Multi-parameter Multiplexing Sensing Based On Two-Dimensional Planar Photonic Crystal Multi-Resonance Mode Defect Cavity

Photonic crystal sensors have the advantages of small size,high resolution,high sensitivity,fast response time,easy integration,no mark detection,and strong anti-interference ability.It is receiving increasing attention from researchers in different application areas.This thesis focuses on the application of multi-parameter multiplexing sensing based on two-dimensional flat photonic crystal multi-resonance mode defect cavity,mainly doing the following work:Firstly,this paper studies the classification and properties of photonic crystal structures,then introduces the concept and properties of planar photonic crystals,and investigates the research and development of photonic crystal multi-parameter sensors and two-dimensional plannar photonic crystal microcavity sensors.The results show it is feasible and necessary to study a multi-parameter sensor based on a photonic crystal,which clarifies the research background and research significance of this topic.Secondly,this paper proposes a two-parameter sensor based on two-dimensional plannar photonic crystal dual-mode L3 microcavity.We optimized the quality factor(Q)of the two resonant modes of the dual-mode L3 microcavity,and then used the two resonant modes of the dual-mode L3 microcavity to achieve refractive index sensing and temperature sensing,respectively.and by using matrix demodulation we achieved simultaneous sensing of these two parameters.In addition,the concept of sensitivity vector space is introduced,which illustrates the construction process of dual-parameter sensing.Thirdly,this paper proposes a three-parameter sensor based on two-dimensional L5 microcavity based on two-dimensional flat photonic crystal.We first optimized the Q and transmission of the three resonant modes of the three-mode L5 microcavity through a large number of simulation analyses.Then based on the three-mode microcavity,we not only realized refractive index sensing and temperature sensing,but also realized pressure sensing by adding a mechanical arm device,and realized simultaneous sensing of three parameters.Finally,we defined the crosstalk between pressure sensing and refractive index sensing and temperature sensing,discussed their interactions,and optimized the simultaneous sensing model.This sensing multiplexing method realizes simultaneous sensing of multiple environmental parameters by using a single photonic crystal microcavity,which can greatly improve the on-chip integration of the photonic crystal sensor and reduce the cost.This idea has broad application prospects and deserves further study.