Polarization Detection Technology Based On Micro-nano Structures

Polarization detection is the technology that mainly deals with the detection of polarization characteristics of light waves.Compared with the intensity detection,polarization detection is focused on the detection of polarization characteristics of light waves,and it has more detailed information of the object to be detected.It increases the information dimensions with its strong advantage in precise object recognition.Because of the demand for real-time detection and system integration and miniaturization,the detection method based on micro-nano gratings has become a recent development trend.Polarization detection is a frontier technology with great development potentials,and it will be widely used in the areas such as object imaging and recognition with multi-dimensional information and the diagnosis of cancers and burns.In this thesis,polarization detection technology based on micro-nano structures has been studied.The main work is divided into the following parts.First of all,in theoretical aspect,this thesis introduces the basic concepts of polarization detection technology,the state of the art of the technology,and the research significance and purpose.In the work,the mechanism of polarization detection and the principle of nano-grating polarization detection technology were introduced.The equivalent medium theory was used to analyze the characteristics of metal wire gratings.In the fabrication,the principle of electron beam lithography,the selection of process parameters and the interactions and influences between the parameters were studied in detail.The working principle and performance parameters of the plasma reactive etching technology were discussed.Multi-vector micropolarizer arrays were designed based on the Stokes theory,and 2×2 polarizer arrays were fabricated.The polarization directions of adjacent micropolarizers are 0,45,90 and 135 degrees.For the performance measurement,the performance detection system of micropolarizers was designed and built,and the methods of calculating the extinction ratio and maximum polarization transmittance were proposed.The performance of micropolarizer arrays was analyzed,and the effects of the depth,period and duty ratio of the aluminum nanowire gratings on the extinction ratio of the incident light were compared with the experimental data.The experimental results were optimized.In practical applications,the polarization imaging detection system based on micropolarizers was designed and implemented.The system was developed to obtain the polarization images of hepatoma cells.Compared with the intensity imaging of hepatoma cells,the advantages of polarization detection based on micro-nano structures were shown.The application prospects of micro-nano polarization detection technology were described.