Kittlaus Eric, Hunacek Jonathon, Bagheri Mahmood, Nejadriahi Hani, Langlois Mehdi, Chiow Sheng-Wey, Yu Nan, Forouhar Siamak
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91009 USA.
EPJ Quantum Technol. 2025;12(1):46. doi: 10.1140/epjqt/s40507-025-00348-z. Epub 2025 Apr 10.
Precise control of atomic systems has led to an array of emerging 'quantum' sensor concepts ranging from Rydberg-atom RF-electric probes to cold-atom interferometer gravimeters. Looking forward, the potential impact of these technologies hinges on their capability to be adapted from laboratory-scale experiments to compact and low-power field-deployable instruments. However, existing setups typically require a bulky and power-hungry laser and optics system (LOS) to prepare, control, and interrogate the relevant atomic system using a variety of frequency-referenced and rapidly reconfigurable laser beams. In this work, we investigate the feasibility of using semiconductor optical amplifiers (SOAs) to replace high-power pump lasers and acousto-optic modulators within a simple atom cooling apparatus, looking forward to the ultimate goal of a space-deployable atom interferometer. We find that existing off-the-shelf SOA components operating at relevant wavelengths for Cs and Rb atom cooling (852 and 780 nm, respectively) are able to permit an attractive combination of rapid (sub-microsecond), high extinction ratio (>60-65 dB) switching while acting as power boosters prior to the atom physics package. These attributes enable a radically different, power-efficient approach to LOS design, reducing or eliminating the need for Watt-class laser amplifiers that are unsuitable for flight deployment. Building on these results, we construct a simple and compact all-semiconductor laser/amplifier LOS for atom cooling that is integrated with custom path-to-flight drive electronics. Up to 125 mW of total optical power is delivered to six fiber-coupled channels for magneto-optical-trap-based cooling of a cloud of neutral Cs atoms. The entire LOS, including reference and cooling laser subsystems and control electronics, occupies a volume of 20×20×15 cm and totals DC power consumption of around 13.5 W, and is designed in a modular format so that additional hardware for synthesizing atom interferometry beams may be added through future development efforts. These results indicate the utility of all-semiconductor laser systems for future low-power flyable atom-based sensor instruments.
对原子系统的精确控制已催生了一系列新兴的“量子”传感器概念，从里德堡原子射频电探针到冷原子干涉重力仪。展望未来，这些技术的潜在影响取决于它们能否从实验室规模的实验转化为紧凑且低功耗的可现场部署仪器。然而，现有的装置通常需要一个庞大且耗电的激光和光学系统（LOS），以便使用各种频率参考和快速可重构的激光束来制备、控制和探测相关的原子系统。在这项工作中，我们研究了在一个简单的原子冷却装置中使用半导体光放大器（SOA）来替代高功率泵浦激光器和声光调制器的可行性，以期实现可在太空部署的原子干涉仪这一最终目标。我们发现，现有的现成SOA组件在用于Cs和Rb原子冷却的相关波长（分别为852和780 nm）下工作时，能够实现快速（亚微秒级）、高消光比（>60 - 65 dB）切换的诱人组合，同时在原子物理组件之前起到功率增强器的作用。这些特性使得LOS设计能够采用一种截然不同的、节能的方法，减少或消除了对不适合飞行部署的瓦级激光放大器的需求。基于这些结果，我们构建了一个简单紧凑的全半导体激光/放大器LOS用于原子冷却，并将其与定制的光路到飞行驱动电子设备集成在一起。高达125 mW的总光功率被输送到六个光纤耦合通道，用于基于磁光阱对中性Cs原子云进行冷却。整个LOS，包括参考和冷却激光子系统以及控制电子设备，占据20×20×15 cm的体积，直流总功耗约为13.5 W，并且采用模块化设计，以便通过未来的开发工作添加用于合成原子干涉测量光束的额外硬件。这些结果表明了全半导体激光系统在未来低功耗可飞行的基于原子的传感器仪器中的实用性。
