The development of ultracompact lightweight optical instrumentation that can be used on-machine and to carry out in-process measurements is vital in realizing improved manufacturing processes, increasing the quality of parts being made while saving time and energy by reducing scrappage rates. Only incremental progress is being made in developing suitable instrumentation based on conventional components, such as traditional refractive elements, as fundamental limits in terms of size and weight are already reached. Here, we demonstrate a chromatic confocal sensor that utilizes the natural chromatic aberration found with a basic hyperbolic metalens to realize an ultracompact and simple probe. Furthermore, we demonstrate how this can be combined with a compact specklemeter as the detection element, thus realizing the whole sensing system in a compact manner. Even with the proof-of-principle instrument in its preliminary and unoptimized state, we achieve the successful recovery of the location of a scatterer, as it is scanned over a 227- $\mu \text{m}$ range, with a standard deviation of error in the position of $1.37~\mu \text{m}$ . Sensors of this form can be deployed in areas where traditional instrumentation would typically impede the manufacturing processes, increasing the number of processes that can have metrology applied directly and providing real-time feedback to improve manufacturing outcomes.

中文翻译：

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基于超紧凑超表面和散斑计的彩色共焦传感器

开发可在机器上使用并进行过程中测量的超紧凑轻型光学仪器对于改进制造工艺、提高零件质量、同时通过降低废品率节省时间和能源至关重要。由于尺寸和重量方面已经达到了基本极限，因此在开发基于传统组件（例如传统折射元件）的合适仪器方面仅取得了渐进的进展。在这里，我们演示了一种色共焦传感器，它利用基本双曲超透镜发现的自然色差来实现超紧凑且简单的探头。此外，我们还演示了如何将其与作为检测元件的紧凑型散斑计相结合，从而以紧凑的方式实现整个传感系统。即使原理验证仪器处于初步且未优化的状态，我们也能成功恢复散射体的位置，因为它是在 227- $\mu \文本{m}$范围，位置误差的标准偏差 $1.37~\mu \text{m}$ 。这种形式的传感器可以部署在传统仪器通常会阻碍制造过程的区域，增加可以直接应用计量的过程数量，并提供实时反馈以改善制造结果。