| So far,the advancement of the nano-meter processing technology has remarkably promoted the research of micro-nano-optical antennas.As shown,the optical antennas can be utilized to rapidly achieve the resonance response and adjustment of incident electromagnetic waves including radar waves and lightwaves,so as to provide a feasible approach for lightwave inducting and manipulating and transporting in featured micro-nano-scale geometry,and thus exhibit a very wide potential application.The focused ion beam and scanning electron microscopy(FIB-SEM)systems with several characters including relatively high beam energy,high processing accuracy and efficiency,and easy technology for fabricating many micro-nano-optical structures,has demonstrated several unique advantages.Considering the factors such as the particular physical principle of the FIB-SEM systems and the processing size still being around 200?m×200?m,the etching capability of current FIB-SEM systems is not suitable to process diverse micro-nano-optical antennas with relatively large structural size,and thus an urgent and important requirement is to remarkably extend the etched size.In this thesis,an improving scheme about the equipment of Helios NanoLab G3 CX of FEI company is setup and thus a precise displacement working platform(PDWP)for fabricating micro-nano-optical antennas with centimeter-scale size is designed and constructed.The main work is as follows:First of all,the main causes of the micro-nano-optical antenna size still being restricted in micron scale,which can be fabricated efficiently by current FIB-SEM systems,are analyzed carefully based on acquired experiences during etching small size optical antennas on different materials selected,and then a miniaturization PDWP scheme,which will be coupled into the equipment of Helios NanoLab G3 CX,is designed.By establishing a mathematical model of permanent magnet synchronous motor,the principle and advantages of the vector controlling for the PDWP are discussed,and then a frequency control of the permanent magnet synchronous motor is determined at I_d=0.A three closed-loop servo control including the current loop,the speed loop,and the position loop,is designed to achieve a high-precision translation and locating of the PDWP.Secondly,the design scheme with key mechanical structures and hardware circuits and software,is concretized.The parameters of the ball screw pairs and the motor model are calculated and determined,and the detailed three-view mechanical structures are constructed.The hardware circuits of the control system is built using DSP and servo control chips,so as to remarkably reduce the calculation of the DSP and also improve the system responsibility.The software programs of debugging servo control system is compiled using CCS integrated development environment.Finally,both the simulation results and the hardware efficiency of the control system are analyzed and evaluated.According to the system simulations and hardware measurements based on MATLAB,it can be seen that the response speed of the servo control system is 0.05s,the control precision is 1?m,the phase current signal waveform is sinusoidal,and the relative speed error is less than 2%.The typical results obtained in the first research course are:micron-scale micro-nano-optical antennas etched over Au and ITO(Indium Tin Oxide)and Si wafer,relatively strong surface plasmons and antenna effect stimulated by lasers of 633nm.The above works lay a key technological and parameter foundation for continuously developing etching process of large size optical antenna through practically using the PDWP developed. |
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