| Image is an important medium for human to recognize and observe the world,and the image information carried by lightwaves can be nicely sensed and analyzed by utilizing the current imaging detection technology for better detecting and recognizing targets.Traditional imaging setups usually exhibit some shortcomings such as low-level photosensitivity and weak adjustability and insufficient multi-mode information capture capability,so as to be difficult to effectively complete target detection with highly sensitivity and dynamic adjustment capacity.So far,the acquirement of developing new detection methods and technologies has become an urgent task and thus received a widespread attention.The basic researches show that a variety of optical antennas exhibit a very nice controllable characteristics in the transmittance and reflectivity and radiance of infrared lightwaves based on exciting surface plasmons.The liquid-crystal microlens controlled electrically can be forced to generate an elastic deformation of liquid-crystal layer through patterned electrode fabricated,and thus possess the performances similar to common optical lenses for completing many complex functions such as the depth of field adjustment,adaptive imaging and 3D imaging.The imaging light-energy collection architecture constructed by integrating a liquid-crystal microlens array and an optical antenna,which is still in the research and development stage currently,has shown a fine prospect on preforming highly efficient light-controlled imaging detection.The continuous development of the driving and controlling signal generators with higher precision and larger array has become an important assignment for achieving highly efficient lightwave control.This dissertation focuses on researching the high-precision and multi-channel electronic driving and controlling devices,as well as the liquid-crystal microlens array with large-area patterned electrode.First of all,the typical characters of the driving and controlling signal for the nano-tip optical antennas and the arrayed liquid-crystal microlens arrays are analyzed.To the high-precision driving and controlling signals for the nano-tip optical antennas,two 16-bit D/A channels are superimposed to output a voltage signal with theoretical resolution higher than 18-bit,and the signals sampled by A/D converter and further regulated by PID controller.The required output accuracy is realized through operations including the chip selection and the circuit optimization and the function fitting.To the 384-channel AC driving and controlling signal for the liquid-crystal microlens arrays,a control strategy using voltage scanning and voltage retention is proposed so as to reduce the D/A conversion channel from 384 to 24 and thus greatly simplify the complexity of the driving and controlling device through analyzing the low-power and capacitive-load characteristics of the liquid-crystal microlenses with planar electrode.Based on the simulation and verification of the signal generation schemes,the mainboard production and code realization of the driving and controlling device are completed.During the process of circuit optimization,the differences among the serial communication,parallel communication and the UART,are compared and analyzed carefully,and also the corresponding improvement measures are proposed based on the limitation of the maximum operating frequency of the MCU.The experiments demonstrate that the driving and controlling device for the nano-tip optical antennas can export high accuracy signals having output error within 0.1m V,and for the liquid-crystal microlens arrays the 384 AC signals with an output error of less than 10% can be realized.Finally,based on the iterative simulation analysis,the design and manufacture of the liquid-crystal microlens arrays with patterned electrode controlled addressably are completed,which are further connected with the driving and controlling device through flexible cable coupling.The optical tests of the nano-tip optical antennas and the liquid-crystal microlens arrays are carried out.The experiments show that the infrared transmittance of the nano-tip optical antennas can be significantly improved as the bias voltage being increased from 0V to 7V.The arrayed liquid-crystal microlens show a good zone focusing character as the driving voltage being varied from 5Vrms to 10 Vrms.The constructed arrayed liquid-crystal microlens driving and controlling systems already lay a foundation for performing zone detection and autofocusing imaging.The built electronic driving and controlling device has demonstrated a stable and effective adjusting performance during imaging detection experiments. |
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