Mahnke J, Kulas S, Geisel I, Jöllenbeck S, Ertmer W, Klempt C
Institut für Quantenoptik, Gottfried Wilhelm Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany.
Rev Sci Instrum. 2013 Jun;84(6):063110. doi: 10.1063/1.4811196.
Laser cooling of atoms usually necessitates several laser frequencies. Alkaline atoms, for example, are cooled by two lasers with a frequency difference in the gigahertz range. This gap cannot be closed with simple shifting techniques. Here, we present a method of generating sidebands at 6.6 GHz by modulating the current of a tapered amplifier, which is seeded by an unmodulated master laser. The sidebands enable trapping of 1.1 × 10(9) (87)Rb atoms in a chip-based magneto-optical trap. Compared to the direct modulation of the master laser, this method allows for an easy implementation, a fast adjustment over a wide frequency range, and the simultaneous extraction of unmodulated light for manipulation and detection. The low power consumption, small size, and applicability for multiple frequencies benefit a wide range of applications reaching from atom-based mobile sensors to the laser cooling of molecules.
原子的激光冷却通常需要几种激光频率。例如，碱金属原子通过频率差在吉赫兹范围内的两台激光器进行冷却。这种频率差无法通过简单的频率偏移技术消除。在此，我们提出一种通过调制锥形放大器的电流来产生6.6吉赫兹边带的方法，该锥形放大器由未调制的主激光器注入种子光。这些边带能够在基于芯片的磁光阱中捕获1.1×10⁹个⁸⁷Rb原子。与直接调制主激光器相比，该方法易于实现，能在很宽的频率范围内快速调整，并且能同时提取未调制光用于操控和探测。其低功耗、小尺寸以及对多种频率的适用性有利于从基于原子的移动传感器到分子激光冷却等广泛的应用。
