Highly efficient and highly versatile method to polarize nuclear-spin by ultrashort laser pulses

我们建立了真空室来极化Yb靶的核自旋，并研制了窄带ns激光系统来对共振激发后的Yb离子进行光学监测。此外，我们从理论上考虑了一种利用一系列短激光脉冲有效地极化目标原子的核自旋的新方案。作为一个具体的例子，我们将这一思想应用于一种奇异原子μ子，并发现5个共振脉冲以1 ps的持续时间和5 ns的时间间隔照射会产生80%的极化。

We have setup the vacuum chamber to polarize nuclear-spin of Yb target, and developed the narrow-band ns laser system to optically monitor the resonantly excited and then photoionized Yb ions. Moreover, we have theoretically considered a new scheme to efficiently polarize nuclear-spin of target atoms using a sequence of short laser pulses. As a specific example we apply the idea to the muonium, a kind of exotic atom, and found that the irradiation of five resonant pulses with a duration of 1 ps and time interval of 5 ns results in 80% polarization.