【摘要】 超长距离的准直细光束在大地测量和空间测量中有广泛的应用价值。用能量守恒法设计的无衍射器件是对数面形，很难用传统的方法加工。采用二元光学方法制成的器件实现了沿光轴方向１０ｍ～１２０ｍ这１１０ｍ的超长距离内，无衍射光束的光斑直径小于５ｍｍ。更多还原

【Abstract】 Alignment beams for extra distance are useful in geodesy and coordinate measurements. An element generating a diffraction free beam designed by the principle of energy conservation is of a logarithmic shape which is difficult to manufacture in the traditional ways. Based on the principle of binary optics, a binary optical element(BOE) is designed that produces a spot diameter less than 5mm from 10m to 120m along optical axis. Experiments show that the alignment distance is sufficiently long. The element lend, itself extremely well to precision alignment.更多还原