Continuous narrowband lasing with coherently driven V-level atoms
Continuous narrowband lasing with coherently driven V-level atoms
复制标题
使用相干驱动的 V 级原子进行连续窄带激光发射
DOI：
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发表时间：
2020
影响因子：
3.3
通讯作者：
H. Ritsch
中科院分区：
文献类型：
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作者：
Christoph Hotter;D. Plankensteiner;H. Ritsch
据预测，衰减率截然不同的 V 级原子的两个跃迁的同时强相干泵浦将在较窄的跃迁上产生几乎完美的反转。以锶中的蓝色和红色跃迁为例，我们表明，在合适的操作条件下，相应的谐振增益可用于在窄跃迁上连续操作激光器。特别是，对于泵浦场相对于窄跃迁的强烈失谐，相干激光发射发生在接近裸原子跃迁频率处，仅表现出散射到激光模式的相干泵浦光的可忽略不计的贡献。腔输出光谱的计算表明，所得激光线宽可以远小于泵浦光的带宽，甚至比窄原子跃迁的自然线宽小。对于正确选择的原子数，其频率与原子跃迁频率密切相关。包括原子运动在内的模拟显示，强跃迁时多普勒冷却，而激光跃迁时小运动加热，因此利用当前的实验技术，在磁光陷阱存在的情况下连续激光操作应该是可能的。
Simultaneous strong coherent pumping of the two transitions of a V-level atom with very different decay rates has been predicted to create almost perfect inversion on the narrower transition. Using the example of the blue and red transitions in Strontium we show that for suitable operating conditions the corresponding resonant gain can be used to continuously operate a laser on the narrow transition. In particular, for a strong detuning of the pump field with respect to the narrow transition, coherent laser emission occurs close to the bare atomic transition frequency exhibiting only a negligible contribution from coherent pump light scattered into the lasing mode. Calculations of the cavity output spectrum show that the resulting laser linewidth can get much smaller than the bandwidth of the pump light and even the natural linewidth of the narrow atomic transition. Its frequency is closely tied to the atomic transition frequency for properly chosen atom numbers. Simulations including atomic motion show Doppler cooling on the strong transition with minor motion heating on the lasing transition, so that continuous laser operation in the presence of a magneto-optical trap should be possible with current experimental technology.