Generation of vortex <i>N</i> ₂ &lt;i/&gt; ⁺ lasing

Abstract

Harnessing structured light is fascinating for its multidisciplinary applications, e.g., in remote driving microrobots, sensing, communications, and ultrahigh resolution imaging. Here, we experimentally demonstrated the generation of a vortex N 2 + lasing pumped by a wavefront structured near-IR femtosecond pulse with orbital angular momentum. The topological charge of the N 2 + lasing was measured to be twofold that of the pump beam. Compared to the case with a pump beam of a plane wavefront, the N 2 + lasing generation efficiency is much higher for the vortex pump beam at high pumping energy, which has a higher clamping intensity by reducing the on-axis plasma density. Our results herald a march toward remote structured N 2 + lasing.