原子干涉仪中激光频率和光强控制系统的设计

为了对铯原子外态干涉仪的激光束精密控制,设计了一套适用于多种需求的激光频率和光强控制系统。该系统基于声光调制器,并集成了激光移频、光强稳定和光强调制等功能。首先,根据原子干涉仪的原理,提出对激光的要求和指标。接着,按照提出的要求设计了集成锁相频率合成器等硬件电路系统和LabVIEW软件控制系统。最后,对所开发的系统进行了实验测试。实验结果表明:系统的移频范围可控制在100~200MHz;光强稳定性好,采用稳光系统后输出光强的波动减小为2%。设计的这套系统功能齐全,可靠有效,实现预期目标,满足原子干涉仪对光学系统的要求。另外此系统还可以应用到其他需要系统中,比如原子钟、原子干涉重力梯度仪等。

Design of laser frequency and power control system in atom interferometer

In order to control laser beams precisely in a caesium atom interferometer, a laser frequency and power control system which is suitable for various demands is designed. Based on an acousto-optical modulator, the system integrates the functions of frequency shift, power stabilization and modulation. Firstly, based on the principle of the atom interferometer, the requirement of the optical part in the system is proposed. Secondly, the hardware circuit system including a phase-locked loop frequency synthesizer and the LabVIEW software control system are designed. Finally, the developed system is tested. The experimental results show that the frequency shift range of the laser beam through the acousto-optical modulator is 100~200MHz;and the power fluctuation of the laser decrease to 2% using the power stabilization system. The designed system has multi-functions, achieves the desired aims and satisfies the requirements of atom transition, matter wave interference and other processes to laser beams. In addition, the designed system could be applied to other systems which need to adjust and control laser beam precisely, such as atomic clock, atom interferometer gravity gradiometer and so on.