Chen Ruiyi, Wang Yanzhi, Shao Jianda, Cao Yu, Zhang Yuhui, Wang Zhihao, Shao Yuchuan, Jin Yunxia, Yi Kui, Leng Yuxin, Li Ruxin
Opt Lett. 2021 Nov 1;46(21):5336-5339. doi: 10.1364/OL.443566.
A low-dispersion mirror (LDM), an important component in ultrafast laser systems, requires both a broad low-dispersion laser-induced damage threshold (LIDT). It is difficult for a traditional quarter-wavelength-based dielectric LDM to achieve these characteristics at the same time. We propose a novel, to the best of our knowledge, low-dispersion mirror (NLDM) that combines periodic chirped layers at the top and alternating quarter-wavelength layers at the bottom. Low dispersion is achieved by introducing a large same group delay (GD) for different wavelengths, so the bandwidth is broadened greatly. In addition, owing to the staggered electric field intensity peak effect in the structure, the NLDM shows the potential for high laser damage resistance. The experiments demonstrated that the NLDM doubles the low-dispersion bandwidth, while the LIDT is also increased compared with the LDM. This novel concept results in improved performance and paves the way toward a new generation of the LDM for ultrafast bandwidth and a high laser applications.
低色散镜（LDM）是超快激光系统中的一个重要组件，它需要具备宽低色散激光诱导损伤阈值（LIDT）。传统的基于四分之一波长的介质低色散镜很难同时实现这些特性。据我们所知，我们提出了一种新型低色散镜（NLDM），它在顶部结合了周期性啁啾层，在底部结合了交替的四分之一波长层。通过为不同波长引入大的相同群延迟（GD）来实现低色散，从而大大拓宽了带宽。此外，由于结构中的交错电场强度峰值效应，NLDM显示出高抗激光损伤的潜力。实验表明，NLDM的低色散带宽增加了一倍，同时与LDM相比，激光诱导损伤阈值也有所提高。这一新颖概念提高了性能，为新一代用于超快带宽和高激光应用的低色散镜铺平了道路。
