Institute of Applied Physics, Russian Academy of Science, 46 Ulyanov Street, Nizhny Novgorod, 603950, Russia.
Opt Lett. 2011 Jun 15;36(12):2296-8. doi: 10.1364/OL.36.002296.
We show that it is possible to produce nearly bandwidth-limited few-cycle attosecond pulses based on periodic resonance interaction of a quasi-monochromatic radiation with the bound states of hydrogenlike atoms. A periodic resonance is provided by a far-off-resonant laser field with intensity much below the atomic ionization threshold via periodic tunnel ionization from the excited states and adiabatic Stark splitting of the excited energy levels. Without external synchronization of the spectral components, it is possible to produce 135 as pulses at 13.5 nm in Li²⁺-plasma controlled by radiation of a mode-locked Nd:YAG laser, as well as 1.25 fs pulses at 122 nm in atomic hydrogen controlled by radiation of a CO₂ laser.
我们证明，通过与类氢原子束缚态的周期性共振相互作用，可以产生几乎带宽受限的少周期阿秒脉冲。通过从激发态周期性隧道电离和激发能级的绝热斯塔克分裂，利用远失谐激光场在强度远低于原子电离阈值的情况下提供周期性共振。在没有光谱分量外部同步的情况下，可以在 Li²⁺-等离子体中产生 135 个 13.5nm 的阿秒脉冲，该等离子体由锁模 Nd：YAG 激光辐射控制，也可以在原子氢中产生 1.25fs 的 122nm 脉冲，该原子氢由 CO₂激光辐射控制。
