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以粒子光学方法为基础,利用适当步长的四阶Runge-Kutta算法模拟研究了准直铬原子束经过波长为425.55 nm,功率分别为3.93 mW和40 mW的一维高斯激光驻波场汇聚作用后所沉积的一维条纹情况。在以上两种激光功率下,沉积条纹沿ox方向的结构质量的周期性相同,而沿着oy方向的结构质量却存在很大的差异:在3.93 mW时,每一根沉积条纹在oy方向上都非常清晰,并且半高宽在[-0.5,0.5](以激光束腰半径为单位)的区域内具有较好的一致性,对比度在[-0.2,0.2]区域内有较好一致性;在40 mW时,每一根沉积条纹呈现出较为复杂的结构,在激光束的中轴区域附近[-1.08,1.08]内,原本在3.93 mW时的一根条纹分裂成三根。另外,3.93 mWH寸y=0的平面内条纹情况和40 mW时y=±1.08平面内情况对应性很好,即平均间距为212.78 nm,半高宽为21.65 nm,对比度为24.78。分析结果表明,较好地沉积条纹与适当激光功率有关。
Based on the particle optics method, a fourth-order Runge-Kutta algorithm with appropriate step size was used to simulate the collimation of a collimated chromium atomic beam in a standing wave field of one-dimensional Gaussian laser with a wavelength of 425.55 nm and power of 3.93 mW and 40 mW respectively After the deposition of one-dimensional stripes of the situation. At the above two laser powers, the periodicity of the structural masses along the ox direction of the deposited stripes is the same, but the structural mass along the oy direction is quite different: at 3.93 mW, each deposited stripe has a periodicity in the oy direction Are very clear, and the FWHM has good consistency in the area of [-0.5, 0.5] (in terms of laser waist radius), and the contrast is better in [-0.2,0.2] area; At 40 mW, each deposited stripe exhibits a more complex structure, splitting a stripe originally at 3.93 mW into three near the central axis of the laser beam [-1.08, 1.08]. In addition, the in-plane fringe pattern of 3.93 mWH-inch y = 0 is very good in the plane of y = ± 1.08 at 40 mW, that is, the average pitch is 212.78 nm, the FWHM is 21.65 nm and the contrast is 24.78. The analysis results show that better deposition of fringes is related to proper laser power.