Two-photon polymerization (TPP) is a powerful technique for direct three-dimensional (3D) micro- and nanomanufacturing owing to its unique ability of writing almost arbitrary structures of various materials. In this paper, a novel method is proposed to quantitatively define and measure the dimensional accuracy of TPP tools based on the concept of instrument transfer function (ITF). A circular linear-chirp pattern is designed for characterizing the ITF. Such a pattern is arranged in a linear chirp function with respect to its radial distance from the pattern centre, thus, well representing a signal with a quasi-flat amplitude over a given spectral bandwidth. In addition, the pattern is rotational symmetric, therefore, it is well suited for characterizing the ITF in different angular directions to detect angular-dependent asymmetries. The feasibility of the proposed method is demonstrated on a commercial TPP tool. The manufactured pattern is calibrated by a metrological large range atomic force microscope (AFM) using a super sharp AFM tip, thus the dimensional accuracy and angular-dependent anisotropy of the TPP tool have been well characterized quantitatively. The proposed method is easy to use and reveals the dimensional accuracy of TPP tools under real manufacturing conditions, which concerns not only the optical focus spot size of the exposing laser but also influencing factors such as material shrinkage, light–matter interaction and process parameters.

双光子聚合 (TPP) 是一种强大的直接三维 (3D) 微纳米制造技术，因为它具有写入各种材料几乎任意结构的独特能力。在本文中，提出了一种基于仪器传递函数 (ITF) 概念的定量定义和测量 TPP 工具尺寸精度的新方法。圆形线性啁啾模式设计用于表征 ITF。这种模式相对于其径向距离以线性线性调频函数排列因此，很好地代表了在给定频谱带宽上具有准平坦幅度的信号。此外，该图案是旋转对称的，因此，它非常适合在不同角度方向表征 ITF，以检测角度相关的不对称性。在商业 TPP 工具上证明了所提出方法的可行性。制造的图案通过使用超锐利 AFM 尖端的计量大范围原子力显微镜 (AFM) 进行校准，因此 TPP 工具的尺寸精度和角度相关各向异性已得到很好的定量表征。所提出的方法易于使用，并揭示了 TPP 工具在实际制造条件下的尺寸精度，