The requirements for dichroic laser mirrors continue to increase with the development of laser technology. The challenge of a dichroic laser mirror coating is to simultaneously obtain spectral performance with significantly different reflection or transmission properties as well as a high laser-induced damage threshold (LIDT) at two different wavelengths. Traditional dichroic laser mirrors composed of alternating high- and low-refractive-index pure materials often has difficulty achieving excellent spectral performance and high LIDTs at two wavelengths simultaneously. We propose to use a new design with mixture layers and sandwich-like-structure interfaces to meet the challenging requirements. An ${\mathrm{Al}}_2{\mathrm{O}}_3-{\mathrm{HfO}}_2$ mixture-based dichroic laser mirror, which can be used as a harmonic separator in a fusion-class laser or a pump/signal beam separator in a petawatt-class Ti-sapphire laser system, is experimentally demonstrated using e-beam deposition. The mixture-based dichroic mirror coating shows good spectral performance, fine mechanical property, low absorption, and high LIDT. For the $s$-polarized 7.7 ns pulses at a wavelength of 532 nm and the $p$-polarized 12 ns pulses at a wavelength of 1064 nm, the LIDTs are almost doubled. The excellent performance of this new design strategy with mixture layers and sandwich-like-structure interfaces suggests its wide applicability in high-performance laser coating.

中文翻译：

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具有混合层和类三明治结构界面的二向色激光镜

随着激光技术的发展，对二向色性激光镜的要求不断增加。二向色性激光镜面涂层的挑战是要同时获得具有显着不同的反射或透射特性以及在两个不同波长下具有较高的激光诱导损伤阈值（LIDT）的光谱性能。由交替的高折射率和低折射率纯材料组成的传统二向色激光镜通常很难同时获得出色的光谱性能和同时在两个波长下获得高LIDT。我们建议使用具有混合层和类似三明治结构的界面的新设计来满足具有挑战性的要求。一个${铝}_2{\mathrm{Ø}}_3-f_2$通过电子束沉积实验证明了基于混合物的二向色性激光镜，该镜可用作聚变级激光器中的谐波分离器或千万瓦级钛蓝宝石激光器系统中的泵浦/信号束分离器。基于混合物的二向色镜面涂层具有良好的光谱性能，优良的机械性能，低吸收率和高LIDT。为了$s$波长为532 nm的7.7 ns偏振脉冲和 $p$如果在1064 nm波长处极化12 ns脉冲，LIDT几乎翻倍。这种具有混合层和类三明治结构界面的新设计策略的出色性能表明其在高性能激光镀膜中的广泛应用。