High Intensity Orbital Angular Momentum: Theory, Generation, and Applications*

Recently, orbital angular momentum (OAM) beams have demonstrated at relativistic intensities at several high-power laser facilities around the world using off-axis spiral phase mirrors [1,2,3]. The additional angular momentum carried by OAM beams, even when linearly polarized, introduces a new control parameter in laser plasma interactions and has shown promise to introduce new and exciting phenomena not possible with a standard Gaussian beam.  

In this talk, we will explore the some of the fascinating potentials of high intensity OAM beams and their interaction with underdense plasma. This will include the interaction of OAM beams with single electrons highlighting ponderomotive trapping, vacuum acceleration, and the coupling of laser OAM to single electrons through ponderomotive forces. We will also discuss the coupling of OAM to plasma electrons through the inverse Faraday effect leading to kilo-Tesla axial magnetic fields and will be demonstrated in 3D PIC simulations [4].

We will conclude the discussion with some recent experimental results of driving wakefields and TNSA with OAM demonstrating enhancements of betatron critical energy, and reduced divergence proton beams [5,6].