The light propagation in the medium normally experiences diffraction, dispersion, and scattering. Studying the light propagation is a century-old problem as the photons may attenuate and wander. We start from the fundamental concepts of the non-diffracting beams, and examples of the non-diffracting beams include but are not limited to the Bessel beam, Airy beam, and Mathieu beam. Then, we discuss the biomedical applications of the non-diffracting beams, focusing on linear and nonlinear imaging, e.g., light-sheet fluorescence microscopy and two-photon fluorescence microscopy. The non-diffracting photons may provide scattering resilient imaging and fast speed in the volumetric two-photon fluorescence microscopy. The non-diffracting Bessel beam and the Airy beam have been successfully used in volumetric imaging applications with faster speed since a single 2D scan provides information in the whole volume that adopted 3D scan in traditional scanning microscopy. This is a significant advancement in imaging applications with sparse sample structures, especially in neuron imaging. Moreover, the fine axial resolution is enabled by the self-accelerating Airy beams combined with deep learning algorithms. These additional features to the existing microscopy directly realize a great advantage over the field, especially for recording the ultrafast neuronal activities, including the calcium voltage signal recording. Nonetheless, with the illumination of dual Bessel beams at non-identical orders, the transverse resolution can also be improved by the concept of image subtraction, which would provide clearer images in neuronal imaging.

光在介质中的传播通常会经历衍射、色散和散射。研究光传播是一个世纪之久的问题，因为光子可能会衰减和漂移。我们从非衍射光束的基本概念开始，非衍射光束的例子包括但不限于贝塞尔光束、艾里光束和马修光束。然后，我们讨论非衍射光束的生物医学应用，重点是线性和非线性成像，例如，光片荧光显微镜和双光子荧光显微镜。非衍射光子可以在体积双光子荧光显微镜中提供散射弹性成像和快速成像。非衍射贝塞尔光束和艾里光束已成功用于体积成像应用，速度更快，因为单个 2D 扫描可提供整个体积的信息，而传统扫描显微镜中采用 3D 扫描。这是具有稀疏样本结构的成像应用的重大进步，尤其是在神经元成像方面。此外，自加速艾里光束结合深度学习算法实现了精细的轴向分辨率。现有显微镜的这些附加功能直接实现了该领域的巨大优势，尤其是在记录超快神经元活动方面，包括钙电压信号记录。尽管如此，在不同阶次的双贝塞尔光束照射下，