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摘要:
为了对飞秒激光系统的群延迟色散(group-delay dispersion,GDD)进行调控,设计并制备了相位延迟反射镜。本文系统地研究了相位延迟反射镜补偿群延迟色散原理,使用Nb2O5和SiO2作为高低折射率材料,并采用将相位延迟反射镜与其互补镜配对的方式平缓了群延迟色散曲线,制备出了相位调控数据为−800 fs2的相位延迟反射镜。该反射镜在900~
1100 nm范围内的反射率达到99%以上,解决了飞秒激光系统带宽调节的问题,满足飞秒激光器的使用要求。Abstract:Phase delay mirrors were designed and prepared to regulate femtosecond laser systems’ group-delay dispersion (GDD). This paper systematically investigates the principle of compensating group-delay dispersion by phase-delay mirrors. Nb2O5 and SiO2 were used as the materials with high and low refractive indices. The group-delay dispersion curves were smoothed out by pairing the phase-delay mirrors with their complementary mirrors. The phase-delayed mirrors with phase modulation data of −800 GDD were prepared, and the reflectivity reached more than 99% in the range of 900 nm−
1100 nm. The bandwidth adjustment problem of femtosecond laser systems is solved to meet the requirements of femtosecond lasers-
Key words:
- group dispersion delay /
- low oscillation /
- reflector /
- broadband modulation /
- phase modulation
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表 1 相位补偿反射镜的技术参数
Table 1. Technical parameters of phase compensation mirrors
参数 具体信息 基板 K9或者石英 入射角度/(°) 0°~3° 反射率/(%) ≥99%@970~ 1100 nmGDD/$ {fs}^{2} $ −800@ 1030 nmGDD/$ {fs}^{2} $ 0@ 1060 nm表 2 薄膜材料沉积工艺参数
Table 2. Film material deposition parameters
材料 Nb2O5 SiO2 基底温度( °C) 145 145 工作真空(Pa) 7.7×10−1 5.2×10−1 沉积速率(nm·s−1) 0.255 0.225 ICP气体 O2+Ar O2+Ar ICP参数 Power: 2.2 kW
电压: 510 V
电流: 14.5 APower: 2.2 kW
电压: 730 V
电流: 8.5 A -
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