We present the design, bench-top setup, and experimental results of a compact heterodyne interferometer that achieves picometer-level displacement sensitivities in air over frequencies above 100 MHz. The optical configuration with spatially separated beams prevents frequency and polarization mixing, and therefore eliminates periodic errors. The interferometer is designed to maximize common-mode optical laser beam paths to obtain high rejection of environmental disturbances, such as temperature fluctuations and acoustics. The results of our experiments demonstrate the short- and long-term stabilities of the system during stationary and dynamic measurements. In addition, we provide measurements that compare our interferometer prototype with a commercial system, verifying our higher sensitivity of 3 pm, higher thermal stability by a factor of two, and periodic-error-free performance.

中文翻译：

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紧凑型高精度无周期误差外差式干涉仪。

我们介绍了紧凑型外差式干涉仪的设计，台式安装和实验结果，该干涉仪在高于100 MHz的频率下在空气中达到皮米级的位移敏感度。具有在空间上分开的光束的光学配置可以防止频率和偏振混合，因此可以消除周期性误差。干涉仪设计用于最大化共模光学激光束路径，以获得对环境干扰（例如温度波动和声音）的高抑制。我们的实验结果证明了在静态和动态测量过程中系统的短期和长期稳定性。此外，我们提供的测量结果将干涉仪原型与商业系统进行了比较，验证了我们的灵敏度更高，为3 pm，热稳定性提高了两倍，