Opt Lett. 2021 Nov 15;46(22):5591-5594. doi: 10.1364/OL.439711.
This study proposes a dark-field confocal microscopy (DFCM) based on fiber-mode excitation-assisted orbital angular momentum annular beam generation with a two-mode fiber to avoid diffraction distortion. The application of optical fibers compresses the DFCM volume, providing new ideas for system miniaturization. System adjustment difficulty is reduced and feasibility is verified by imaging 2D and 3D samples. High imaging contrast is achieved by fully blocking the reflected light and annular illumination with a steady central dark-spot within a propagation distance of 3 m. The application of our scheme can be further extended to detect subsurface defects in optical components and high-contrast biological imaging.
本研究提出了一种基于暗场共焦显微镜（DFCM）的方法，通过光纤模式激励辅助轨道角动量环形光束产生，结合双模光纤避免了衍射失真。光纤的应用压缩了 DFCM 的体积，为系统小型化提供了新的思路。通过对 2D 和 3D 样品进行成像，降低了系统调节难度并验证了其可行性。在 3 米的传播距离内，通过完全阻挡反射光和环形照明，并形成稳定的中心暗点，实现了高对比度的成像。我们的方案可以进一步扩展到光学元件的亚表面缺陷检测和高对比度生物成像。
