近230纳米的稳健瓦级连续波深紫外激光器
Robust watt-level continuous-wave deep-ultraviolet lasers near 230 nm
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中文总结 AI 辅助
该研究基于欧洲6个实验室的4年运行经验，开发出VECSEL基的紧凑低成本DUV激光器，通过对比不同BBO腔设计优化性能，实现了近230纳米的瓦级连续波DUV激光，经相关实验验证有效。
中文摘要 AI 辅助
近230纳米的连续波（CW）深紫外（DUV）激光器可实现AlF、Cd和Zn的激光冷却，但低于237纳米的二次谐波产生实际依赖于β-偏硼酸钡（BBO），其走离效应和紫外诱导降解阻碍了持续运行。我们展示了基于垂直外腔面发射激光器（VECSEL）的紧凑、低成本系统，该系统基于在欧洲6个实验室的12套激光系统中运行14个DUV腔的4年经验开发。外部LBO腔在463纳米处产生近4瓦的功率，腔效率达94%。我们对比了球面和椭圆聚焦的布鲁斯特切割BBO腔与正入射增透（AR）涂层设计：AR涂层腔实现了最高功率和效率，达到1.0瓦，腔效率51%、外部效率44%；球面布鲁斯特腔达到700毫瓦，且在70小时以上保持恒定的腔内功率；椭圆聚焦将峰值强度降低6倍并改善了光束质量，尽管对准敏感性更高。合作设计的DUV光学器件、AlF光谱学及Cd俘获验证了该系统。
英文摘要
Continuous-wave (CW) deep-ultraviolet (DUV) lasers near 230~nm enable laser cooling of AlF, Cd, and Zn, but second-harmonic generation below 237~nm relies in practice on beta-barium borate (BBO), whose walk-off and UV-induced degradation hinder sustained operation. We demonstrate compact, affordable VECSEL-based systems informed by four years of operating 14 DUV cavities in 12 laser systems across six European laboratories. External LBO cavities produce nearly 4~W at 463~nm with 94% cavity efficiency. We compare spherically and elliptically focused Brewster-cut BBO cavities with a normal-incidence AR-coated design. The AR-coated cavity delivers the highest power and efficiency, reaching 1.0~W at 51% cavity and 44% external efficiency; the spherical Brewster cavity reaches 700~mW and maintains constant circulating power over 70~h, while elliptical focusing reduces peak intensity sixfold and improves beam quality, albeit with greater alignment sensitivity. Collaboration-designed DUV optics, AlF spectroscopy, and Cd trapping validate the system.
