Abstract

Two ultrastable laser systems for the clock transition spectroscopy in the strontium frequency standard are developed. The high stability of laser radiation frequency is provided by the active loop for frequency referencing to the Fabry–Perot reference cavity. The used cavities are made of glass with ultra-low thermal expansion coefficient and are 48 cm long which provides an extremely low thermal noise limit of 7 × 10^–17. The relative frequency drift velocity of laser systems is 216 mHz/s which allows the implementation of high-accuracy spectroscopy of the clock transition in strontium.

中文翻译：

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相对分数频率漂移率低于5×10 –16 / s的长ULE腔，用于稳定激光频率

摘要

开发了两种用于锶频率标准的时钟跃迁光谱学的超稳定激光系统。有源回路为法布里-珀罗基准腔的频率提供了很高的激光辐射频率稳定性。所使用的空腔由具有超低热膨胀系数的玻璃制成，长48厘米，提供了极低的7×10 ^–17的热噪声极限。激光系统的相对频率漂移速度为216 mHz / s，可实现锶中时钟跃迁的高精度光谱。