JASLab, University of Ottawa and National Research Council, 100 Sussex Drive, Ottawa, Canada.
Phys Rev Lett. 2011 May 13;106(19):193002. doi: 10.1103/PhysRevLett.106.193002. Epub 2011 May 10.
The balance of the linear photon momentum in multiphoton ionization is studied experimentally. In the experiment argon and neon atoms are singly ionized by circularly polarized laser pulses with a wavelength of 800 and 1400 nm in the intensity range of 10(14)-10(15) W/cm2. The photoelectrons are measured using velocity map imaging. We find that the photoelectrons carry linear momentum corresponding to the photons absorbed above the field free ionization threshold. Our finding has implications for concurrent models of the generation of terahertz radiation in filaments.
实验研究了多光子电离中线性光子动量的平衡。在实验中，氩和氖原子分别用波长为 800nm 和 1400nm 的圆偏振激光脉冲在 10(14)-10(15) W/cm2 的强度范围内进行单电离。使用速度映射成像测量光电子。我们发现光电子携带线性动量，该动量对应于在无场电离阈值以上吸收的光子。我们的发现对细丝中太赫兹辐射产生的并发模型有影响。
