Stringent conditions on the phase relation of multiple photons are a prerequisite for novel protocols of high-resolution coherent spectroscopy. In a recent experiment, we have implemented an interrogation process of a ${\mathrm{Ca}}^{+}$-ion cloud based on three-photon coherent population trapping, with the potential to serve as a frequency reference in the THz range. This high-resolution interrogation has been made possible by phase-locking both laser sources for cooling and repumping of the trapped ions to a clock laser at 729 nm by means of an optical frequency comb. The clock laser, a titanium-sapphire laser built in our lab locked onto two high-finesse cavities reaches a linewidth of a few Hertz and a frequency stability below ${10}^{-14}$ at 1 s, performances which can be copied onto the two other sources. In this paper, we discuss the performances of the phase transfer between the three involved lasers via the optical frequency comb.

中文翻译：

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三个可见光激光器之间的相转移，以进行相干阱俘获

多个光子的相位关系上的严格条件是高分辨率相干光谱新协议的前提。在最近的实验中，我们实施了对${钙}^{+}$离子云基于三光子相干人口陷阱，具有在太赫兹范围内作为频率参考的潜力。通过使用光学频率梳将两个用于冷却和重新注入离子的激光源锁相到729 nm的时钟激光器，可以实现这种高分辨率的询问。时钟激光器是我们实验室中内置的钛-蓝宝石激光器，锁定在两个高级腔上，其线宽达到几赫兹，频率稳定性低于${10}^{-14}$在1 s时，可以将表演复制到其他两个来源上。在本文中，我们讨论了通过光频率梳在三个所涉及的激光器之间进行相移的性能。