Miao B, Feder L, Shrock J E, Goffin A, Milchberg H M
Institute for Research in Electronics and Applied Physics University of Maryland, College Park, Maryland 20742, USA.
Phys Rev Lett. 2020 Aug 14;125(7):074801. doi: 10.1103/PhysRevLett.125.074801.
We demonstrate a new highly tunable technique for generating meter-scale low density plasma waveguides. Such guides can enable laser-driven electron acceleration to tens of GeV in a single stage. Plasma waveguides are imprinted in hydrogen gas by optical field ionization induced by two time-separated Bessel beam pulses: The first pulse, a J_{0} beam, generates the core of the waveguide, while the delayed second pulse, here a J_{8} or J_{16} beam, generates the waveguide cladding, enabling wide control of the guide's density, depth, and mode confinement. We demonstrate guiding of intense laser pulses over hundreds of Rayleigh lengths with on-axis plasma densities as low as N_{e0}∼5×10^{16} cm^{-3}.
我们展示了一种用于产生米级低密度等离子体波导的新型高度可调谐技术。这种波导能够在单个阶段实现激光驱动电子加速至数十GeV。等离子体波导通过两个时间分离的贝塞尔光束脉冲诱导的光场电离在氢气中形成：第一个脉冲，即J₀光束，产生波导的核心，而延迟的第二个脉冲，这里是J₈或J₁₆光束，产生波导包层，从而能够对波导的密度、深度和模式限制进行广泛控制。我们展示了在轴上等离子体密度低至Ne0∼5×10¹⁶ cm⁻³的情况下，强激光脉冲在数百个瑞利长度上的导引。
