Peking University’s DC-SRF-II photoinjector drive laser system
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摘要: 为满足北京大学新一代超导注入器DC-SRF-II注入器的需求,设计了新的光阴极驱动激光系统。系统采用模块化的布局,可以工作在从单脉冲到81.25 MHz连续波模式,绿光输出功率1.41 W @ 1 MHz。系统实现了激光的纵向和横向整形,纵向整形后的激光脉冲为平顶分布,脉宽约为18 ps,横向则为截断高斯分布。实验结果显示,输出激光的RMS功率波动为1.8%,指向抖动小于1 μrad。Abstract: A new drive laser system was developed to meet the requirement of DC-SRF-II photoinjector at Peking University. This modular drive laser system can operate from single pulse to 81.25 MHz CW mode, with green light output power 1.41 W @ 1 MHz. Longitudinal and transverse shaping were also implemented in the system, resulting in near flat-top 18 ps laser pulse with cut-Gaussian transverse profile. The stability measurement shows that the system output power stability is 1.8% RMS, and the pointing stability is less than 1 μrad.
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Key words:
- photocathode /
- photocathode drive laser /
- laser shaping /
- laser transport
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图 1 北京大学DC-SRF注入器双碱光阴极驱动激光系统
Figure 1. Peking University’s DC-SRF injector photocathode drive laser system
① seed source, ② amplification system, ③ frequency doubling system, ④ longitudinal shaping system, ⑤ cross-correlation measurement system, ⑥ transverse shaping system, ⑦ laser transmission system
表 1 放大器的输出参数表
Table 1. DC-SRF-II laser amplifier parameters
output power 21 W @ 10 MHz 20.5 W @ 81.25 MHz 2.2 W @ 1 MHz spectral width < 3 nm, @ 1037 nm pulse energy 2 µJ @ 10 MHz pulse width 1.5 ps @ 10 MHz & 1 MHz 4 ps @ 81.25 MHz M2 <1.3 -
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