Wang Yu, Li Huaming, Hu Qinglei, Cheng Xiaofeng, Chen Ruixi, Lv Xiaohua, Zeng Shaoqun
Opt Express. 2020 Sep 28;28(20):29904-29917. doi: 10.1364/OE.405532.
Large aberrations are induced by non-collimated light when the convergence or divergence of the incident beam on the back-pupil plane of the objective lens is adjusted for 3D non-inertial scanning. These aberrations significantly degrade the focus quality and decrease the peak intensity of the femtosecond laser focal spot. Here, we describe an aberration-corrected 3D non-inertial scanning method for femtosecond lasers based on a digital micromirror device (DMD) that is used for both beam scanning and aberration correction. An imaging setup is used to detect the focal spot in the 3D space, and an iterative optimization algorithm is used to optimize the focal spot. We demonstrate the application of our proposed approach in two-photon imaging. With correction for the 200-µm out-of-focal plane, the optical axial resolution improves from 7.67 to 3.25 µm, and the intensity of the fluorescence signal exhibits an almost fivefold improvement when a 40× objective lens is used. This aberration-corrected 3D non-inertial scanning method for femtosecond lasers offers a new approach for a variety of potential applications, including nonlinear optical imaging, microfabrication, and optical storage.
在对物镜后光瞳平面上的入射光束的会聚或发散进行调整以用于三维非惯性扫描时，非准直光会引起较大像差。这些像差会显著降低聚焦质量，并降低飞秒激光焦点的峰值强度。在此，我们描述一种基于数字微镜器件（DMD）的飞秒激光像差校正三维非惯性扫描方法，该数字微镜器件用于光束扫描和像差校正。使用成像装置来检测三维空间中的焦点，并使用迭代优化算法来优化焦点。我们展示了我们提出的方法在双光子成像中的应用。在校正200微米的离焦平面时，当使用40倍物镜时，光轴分辨率从7.67微米提高到3.25微米，并且荧光信号强度提高了近五倍。这种用于飞秒激光的像差校正三维非惯性扫描方法为包括非线性光学成像、微加工和光存储在内的各种潜在应用提供了一种新方法。
