We present a Target Positioning Interferometer (TPI), a system that uses variations of the wavefront curvature to position solid reflective surfaces with submicrometric precision. The TPI is a Michelson interferometer into which a lens is inserted in the target arm and the mirror of the reference arm is slightly tilted. The TPI configuration presented in this work allows us to position the surface of a reflective target on a beam focus within an uncertainty of 350 nm (2σ) in a subsecond timeframe, using a lens with a numerical aperture of NA = 0.20. We support our experimental findings with numerical simulations of the interference pattern using the ABCD matrices' method, allowing us to define scaling laws for using the TPI with different optics and environments, as well as suggestions to improve the TPI accuracy and adapt the system to different applications. This system is very well suited for accurate and repeatable target positioning used in laser-driven ion acceleration, where a precise alignment is key to optimize the proton acceleration mechanism.

中文翻译：

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使用迈克尔逊干涉测量法对平面反射面进行亚微米绝对定位

我们提出了目标定位干涉仪 (TPI)，该系统使用波前曲率的变化以亚微米精度定位固体反射表面。TPI 是一种迈克尔逊干涉仪，在目标臂中插入一个透镜，参考臂的反射镜稍微倾斜。这项工作中提出的 TPI 配置允许我们使用数值孔径为 NA = 0.20 的透镜在亚秒时间范围内将反射目标的表面定位在光束焦点上，不确定度为 350 nm (2σ)。我们通过使用 ABCD 矩阵的方法对干涉图案进行数值模拟来支持我们的实验结果，使我们能够定义在不同光学器件和环境中使用 TPI 的缩放定律，以及提高 TPI 精度和使系统适应不同应用的建议。该系统非常适用于激光驱动离子加速中使用的精确且可重复的目标定位，其中精确对准是优化质子加速机制的关键。