一种用于Yb:YAG激光器的波长分离膜的研制

以1 030 nm高反,940,980 nm高透的波长分离膜作为实例,为提高该薄膜元件的波长分离效果,从膜系的优化方面做了一系列的研究,诸如采用带通滤光片的设计思想,在膜堆两侧加入了匹配层,调整膜堆的周期厚度,并用膜系设计软件对通带作进一步的优化.通过这一系列的优化设计后,利用RF双离子束溅射工艺在BK7玻璃基底上沉积样品薄膜,并在基底背面加镀通带增透膜.结果显示,透射带在940和980 nm处的透过率分别为97.73%和93.63%,反射带在1 030 nm的反射率为99.99%.对所制备的样品薄膜进行了激光损伤阈值测量,得到了35 J/cm2(1 064 nm,12 ns)的结果.

A wavelength separation multilayer for Yb:YAG laser

A wavelength separation multilayer with high reflectivity at 1 030 nm and high transmittance at 940 and 980 nm was obtained by optimizing the film stack, such as inserting matching layers, tuning the periodic thickness with the help of thin film design software. The Fabry-Perot configuration was adopted to increase the transmitiance of pass-band. This applicable sample multilayer was carried out by dual ion beam sputtering on BK7 glass. The testing result shows that transmittances of 97.73% and 93.63% are obtained at 940 nm and 980 nm, respectively. A laser induced damage threshold (LIDT) of 35 J/cm2 (1 064 nm, 12 ns) of the separation film is characterized with self-made testing facility.