A major challenge in three-dimensional (3D) microscopy is to obtain accurate spatial information while simultaneously keeping the microscopic samples in their native states. In conventional 3D microscopy, axial resolution is inferior to spatial resolution due to the inaccessibility to side scattering signals. In this study, we demonstrate the isotropic microtomography of free-floating samples by optically rotating a sample. Contrary to previous approaches using optical tweezers with multiple foci which are only applicable to simple shapes, we exploited 3D structured light traps that can stably rotate freestanding complex-shaped microscopic specimens, and side scattering information is measured at various sample orientations to achieve isotropic resolution. The proposed method yields an isotropic resolution of 230 nm and captures structural details of colloidal multimers and live red blood cells, which are inaccessible using conventional tomographic microscopy. We envision that the proposed approach can be deployed for solving diverse imaging problems that are beyond the examples shown here.

三维（3D）显微镜的主要挑战是获得准确的空间信息，同时将显微镜样品保持在其原始状态。在传统的3D显微镜中，由于无法获得侧面散射信号，因此轴向分辨率不如空间分辨率。在这项研究中，我们通过光学旋转样品来证明自由浮动样品的各向同性显微断层照相术。与以前使用带有多个焦点的光镊的方法相反，这些镊子仅适用于简单的形状，我们开发了3D结构的光阱，该光阱可以稳定地旋转独立的复杂形状的显微样品，并在各种样品方向上测量侧向散射信息以实现各向同性分辨率。所提出的方法产生230 nm的各向同性分辨率，并捕获了胶体多聚体和活血红细胞的结构细节，而这是使用常规层析X射线显微镜无法达到的。我们设想可以将所提出的方法用于解决超出此处所示示例的各种成像问题。