Influence of laser power on deposition of the chromium atomic beam in laser standing wave

Abstract

One-dimensional deposition of collimated Cr atomic beam focused by a near-resonant Gaussian standing-laser field with wavelength of 425.55 nm is examined from particle-optics approach by using an adaptive step size, fourth-order Runge-Kutta type algorithm. The influence of laser power on deposition of atoms in laser standing wave is discussed and the simulative result shows that the FWHM of nanometer stripe is 102 nm and contrast is 2 : 1 with laser power equal to 3 mW, the FWHM is 1.2 nm and contrast is 32 : 1 with laser power equal to 16 mW, but with laser power increase, equal to 50 mW, the nonmeter structure forms the multi-crests and exacerbates.atom lithography, laser standing wave, laser power Direct writing atom lithography is a new technique in which resonant light is used to pattern an atomic beam and the nanostructures are formed when the atoms deposit on the substrate. Compared with the conventional optical lithography, the atom lithography technique in performance has potential advantages. The process of atom lithography is based on two different types of interactional forces that can be used to manipulate neutral atoms by laser field, the atomic beam is collimated and the standing-wave field acts like an array of cylindrical lenses and can focus them onto the substrate and then form the nanometre structure, the spacing between the lines is predictably coincident with the half-wavelength of the optical standing-wave that is used as a light mask [1][2][3] .Since the purpose of direct write atomic lithography is to deposit small features, any influence that contribute to a broadening of the features must be considered [4] . Based on the semi-classical model in this paper, we analyze the motion equation of atoms in the laser standing wave field, and then get the trajectory of the atoms in the standing wave field by analytical simulation. Basing on these analyses, we put the emphasis on the effect of laser power in standing wave for the nanometer structure's characteristic. The simulation results have shown that suitable laser power is very important for depositing fine nanometer structure with direct-write atom lithography.