原子运动速度对激光驻波场作用下纳米光栅沉积特性的影响

摘要

The deposition patterns of neutral chromium atoms in a laser standing wave with different longitudinal and transverse velocities are discussed. The simulation results of atoms show that the full width at half maximum ( FWHM ) of a nanometer stripe is 1. 49 nm and the contrast is 62. 1: 1 when the ideal longitudinal velocity of chromimum atom is the most probable velocity 960 m/s, the FWHM of the stripe is 5. 35nm and the contrast is 25. 6: 1 when the longitudinal velocity of chromimum atom is half the most probable velocity. The simulation results of deposition with different transverse velocities are shown at the same time, the FWHM of the stripe is 4. 18nm and the contrast is 20. 9: 1, with the transverse velocity of chromimum atom being 0. 25 m/s; the FWHM of the stripe is 58. 4 nm and the contrast is 8. 9: 1, with the transverse velocity of chromimum atom being 0. 50 m/s.%利用近共振激光驻波场操纵中性原子实现纳米光栅的沉积是一种新型的研制纳米结构方法,处于激光驻波场中的原子运动速度特性对最终纳米光栅的沉积特性有着重要的影响.利用半经典理论,基于4阶Runge-Kutta算法进行了不同铬原子纵向和横向运动速度条件下纳米光栅结构沉积的仿真研究.研究表明,铬原子纵向速度为最大概率速度960 m/s时,所形成的纳米光栅的半高宽为1.49 nm,对比度为62.1∶1,当铬原子的纵向速度为半最大概率速度480 m/s时,纳米光栅的半高宽为5.35 nm,对比度下降为25.6∶1.同时,对原子的横向速度影响沉积特性的研究表明,当原子的横向运动速度为0.25 m/s时,纳米光栅结构的半高宽为4.18 nm,条纹对比度为20.9∶1,当原子的横向运动速度为0.50 m/s时,纳米光栅结构的半高宽变为58.4 nm,条纹对比度减小为8.9∶1,沉积条纹质量下降.