Self-waveguiding of relativistic laser pulses in neutral gas channels

Journal article

We demonstrate that an ultrashort high intensity laser pulse can propagate for hundreds of Rayleigh ranges in a prepared neutral hydrogen channel by generating its own plasma waveguide as it propagates; the front of the pulse generates a waveguide that confines the rest of the pulse. A wide range of suitable initial index structures and gas densities will support this “self-waveguiding” process; the necessary feature is that the gas density on axis is a minimum. Here, we demonstrate self-waveguiding of pulses of at least 1.5 × 1017 W/cm2 (normalized vector potential a0 ∼ 0.3) over 10 cm, or ∼100 Rayleigh ranges, limited only by our laser energy and length of our gas jet. We predict and observe characteristic oscillations corresponding to mode-beating during self-waveguiding. The self-waveguiding pulse leaves in its wake a fully ionized low-density plasma waveguide which can guide another pulse injected immediately following; we demonstrate optical guiding of such a follow-on probe pulse. The method is well suited to laser wakefield acceleration and other applications requiring a long laser-matter interaction length.

Authors: Feder, L; Miao, B; Shrock, JE; Goffin, A; Milchberg, HM

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Physical Society
• Journal: Physical Review Research
• Volume: 2
• Issue: 4
• Article number: 43173
• Publication date: 2020-11-03
• Acceptance date: 2020-10-12
• DOI: 10.1103/physrevresearch.2.043173
• EISSN: 2643-1564
• Language: English
• Keywords: FFR