High-reflective multilayer laser coatings are widely used in advanced optical systems from high power laser facilities to high precision metrology systems. However, the real interface quality and defects will significantly affect absorption/scattering losses and laser induced damage thresholds of multilayer coatings. With the recent advances in the control of coating design and deposition processes, these coating properties can be significantly improved when properly engineered the interface and defects. This paper reviews the recent progress in the physics of laser damage, optical losses and environmental stability involved in multilayer reflective coatings for high power nanosecond near-infrared lasers. We first provide an overview of the layer growth mechanisms, ways to control the microstructures and reduce layer roughness, as well as the nature of defects which are critical to the optical loss and laser induced damage. Then an overview of interface engineering based on the design of coating structure and the regulation of deposition materials reveals their ability to improve the laser induced damage threshold, reduce the backscattering, and realize the desirable properties of environmental stability and exceptional multifunctionality. Moreover, we describe the recent progress in the laser damage and scattering mechanism of nodule defects and give the approaches to suppress the defect-induced damage and scattering of the multilayer laser coatings. Finally, the present challenges and limitations of high-performance multilayer laser coatings are highlighted, along with the comments on likely trends in future.

高反射多层激光镀膜广泛用于从高功率激光设备到高精度计量系统的先进光学系统。然而，真实的界面质量和缺陷会显着影响多层涂层的吸收/散射损耗和激光诱导的损伤阈值。随着最近在控制涂层设计和沉积过程方面取得的进展，当适当地设计界面和缺陷时，这些涂层性能可以得到显着改善。本文回顾了高功率纳秒近红外激光器多层反射涂层所涉及的激光损伤、光学损耗和环境稳定性物理方面的最新进展。我们首先概述了层生长机制、控制微结构和降低层粗糙度的方法，以及对光学损耗和激光引起的损伤至关重要的缺陷的性质。然后，基于涂层结构设计和沉积材料调节的界面工程概述揭示了它们能够提高激光诱导损伤阈值、减少后向散射，并实现环境稳定性和卓越多功能性的理想特性。此外，我们描述了结节缺陷的激光损伤和散射机制的最新进展，并给出了抑制多层激光涂层的缺陷引起的损伤和散射的方法。最后，强调了高性能多层激光涂层目前的挑战和局限性，以及对未来可能趋势的评论。