Study On Infrared Detection Key Technology Based On Integrating Liquid-Crystal Filtering And Zooming Adjusted Electrically

Recently,the infrared detection technology with several remarkable advantages of day-and-night working and excellent adaptability to environment medium and targets,has been developed rapidly and then widely utilized in many application fields such as typical earth recourse survey,biomedical diagnosis,food safety supervision and so on.In this thesis,the infrared detection key technology based on integrating liquid-crystal?LC?filtering and zooming adjusted electrically has been carefully studied.According to the multi-beam interference in a Fabry-Perot?FP?micro-cavity and the LC birefringence controlled electrically,an integrated LC chip prototype has been designed and fabricated by combining a small or miniaturized optical filter and an arrayed microlens with electrically tunable focal length.The developed LC chip can be driven by a relatively low signal voltage of less than²2.0 V_rms,so as to perform effectively operations including electrically selecting and further adjusting the wavelength of transmission lightwaves and simultaneously zooming of arrayed LC microlens for conducting light-field imaging.The main work of this thesis is as follows.Firstly,the structural model of the integrating filtering and zooming architecture was proposed.Based on the LC elastic theory and the free energy minimum criterion,the difference-iterative method was used to calculate the spatial distribution of LC directors,and the transmission spectrum and zooming characteristics were further simulated and analyzed.Secondly,zinc selenide wafers with a typical infrared transmittance of more than 70%were used as the substrates of the LC chip,and then the patterned electrode with arrayed micro-hole was designed and fabricated in an aluminum film of²0 nm thickness,which was determined experimentally.The integrating LC chip with filtering and zooming adjusted electrically was fabricated successfully.Finally,the key characteristics of the integrating LC chip including the infrared transmission spectrum and the point spread function for further conducting light-field imaging,were measured at different signal voltage applied over the chip.The experimental results show that the wavelength selection and further adjustment in a relatively wide wavelength range including near,middle and far infrared band,and the corresponding average peak transmittance being²8%,¹9%and¹2%,and the electrically tunable focusing,can also be performed,simultaneously.The integrating LC chip with both the filtering and zooming function developed by us demonstrate several remarkable advantages,such as multi-function integration,wide band operation,low signal voltage regulation,lightness and sensitivity,so as to lay a technical foundation for further developing infrared spectral light-field imaging technology.