搭建了能够在二维方向上实现纳米级定位的二维自动定位系统。首先, 加工了栅格间距为5 μm的64×64编码的透射式二维零位光栅; 然后, 分析设计了光栅系统光电转换电路和数据控制电路, 实现了系统数据采集、显示和运动控制等功能。在此基础上搭建了基于二维零位光栅的纳米定位系统, 并利用积分法实现了二维方向的自动定位。实验结果表明, 系统定位速度对透射光强分布具有很高的依赖性, 系统一次定位的成功率与初始位置密切相关。若起始位置在以零位为中心, 半径为2.5 μm圆形区域内, 系统可实现纳米量级定位对准; 当起始位置在以零位为中心, 5～200 μm为半径的圆环范围内, 自动定位可能存在盲点, 但通过改变初始位置重新进行搜索, 仍然能够准确地实现纳米定位。

An automatic positioning system using a pair of two-dimensional (2-D) zero-reference gratings was established to implement the nano-positioning in 2D directions. Firstly, the 64×64 coded 2-D zero-reference gratings with a grid width of 5 μm was designed and fabricated. Then, the photoelectric conversion circuit and control circuit were built for the automatic nano-positioning system to implement data acquisition, display and motion control and other functions. Finally, an automatic positioning algorithm using an integral method was proposed to achieve the automatic positioning in 2D directions. The results show that the system positioning speed depends on the transmittance of light intensity distribution and the positioning success rate is related to the starting position. If the starting position is located in the central circular area with a radius of 2.5 μm, this equipment may achieve nanoscale positioning. If the starting position is located in the central circular area with a radius range of 5—200 μm, the automatic alignment may present blind spots. In this case, the starting positions should be changed to perform the positioning process again and the alignment will be achieved successfully.