光学学报, 2017, 37 (6): 0614004, 网络出版: 2017-06-08
直边衍射驻波场中铬原子三维沉积特性分析
Analysis of Three-Dimensional Deposition Characteristics of Chromium atoms in the Straight Edge Diffraction Standing Wave Field
激光光学 直边衍射 三维沉积特性 龙格-库塔法 laser optics straight edge diffraction three-dimensional deposition characteristics Runge-Kutta method
摘要
利用近共振激光驻波场操纵中性原子实现纳米级条纹沉积是一种新型的研制纳米结构长度标准传递方法。在会聚原子过程中, 由于沉积基片的存在, 激光驻波场内会产生直边衍射现象, 从而影响原子的运动轨迹及沉积光栅。建立了直边衍射扰动下激光驻波场模型, 通过四阶龙格-库塔法, 对铬原子的三维运动轨迹及沉积效果进行仿真。考虑到激光功率与失谐量的影响, 从半峰全宽(FWHM)和对比度入手, 对铬原子运动轨迹及沉积条纹特性进行分析。结果表明, 当激光功率为3.93 mW, 失谐量为200 MHz时, 原子沉积光栅的FWHM为6.043 nm, 对比度为0.863, 原子沉积光栅的质量最佳。与经典模型相比, 该模型考虑了驻波场中直边衍射的影响, 所得模拟结果更接近实际, 对实验有理论指导意义。
Abstract
Nanostructures stripe deposition technique is a new method to develop nanostructures length standard transmission with the near resonance laser standing wave field manipulation in neutral atoms. In the process of focusing atoms, due to the presence of deposition substrate, a straight edge diffraction phenomenon occurs in the laser standing wave field, which affects the atomic trajectory and deposition grating. The model of laser standing wave field is established under the straight edge diffraction disturbance, and the three-dimensional trajectory and deposition characteristics of chromium atoms are simulated using the Runge-Kutta method. Considering the influence of laser power and detuning amount, we analyze the trajectory and deposition characteristics of chromium atoms from the full width at half maximum (FWHM) and the contrast. The results show that when the laser power and the detuning amount are 3.93 mW and 200 MHz, the FWHM and contrast of atomic deposition grating are 6.043 nm and 0.863, respectively. Under this condition, the best quality of atomic sedimentary grating can be acquired. Compared with the classical model, this model has considered the influence of standing wave field of straight edge diffraction disturbance, the simulation results are closer to the actual situation and can be theoretical guidance to the experiment.
伊路福, 熊显名, 张文涛, 占平平. 直边衍射驻波场中铬原子三维沉积特性分析[J]. 光学学报, 2017, 37(6): 0614004. Yi Lufu, Xiong Xianming, Zhang Wentao, Zhan Pingping. Analysis of Three-Dimensional Deposition Characteristics of Chromium atoms in the Straight Edge Diffraction Standing Wave Field[J]. Acta Optica Sinica, 2017, 37(6): 0614004.