随着氧碘化学激光器(COIL)输出功率的不断提高,传统的膜系设计已不能满足要求.在倍频膜系的设计基础上,优化设计出了激光45°入射时对1 315 nm和632.8 nm双波长高反(HR)并在1 315 nm处具有90°位相延迟的高反射镜,其基底材料为融石英,高折射率材料为ZrO₂,低折射率材料为SiO₂.然后,采用电子束蒸发手段制备了口径为200mm的高反射位相延迟镜.最后对该延迟镜的性能进行了测试,结果表明:对632.8 nm波长的反射率大于等于95.0%,对1 315 nm波长的反射率大于等于99.8%,位相延迟在90.235°～95.586°范围内.

With the continuous increase of COIL output power, the conventional HR film stack gradually can't satisfy the practical requirements. In this paper, on the base of multiple frequency film stack, a φ200 mm HR phase retardance mirror at 45° incidence is designed and fabricated by e-beam evaporation equipment. The substrate is fused silica, and the high and low refractive index materials are ZrO₂ and SiO₂ respectively. The measured results show that the reflectivity at 632.8 nm is no less than 95.0%, the reflectivity at 1 315 nm is no less than 99.8%, and phase retardance at 1 315 nm is 90.235°～95.586°.