Mid-infrared strong field ionization angular distributions
We present a study of the photoelectrons energy distribution from ionization of Argon by a linearly polarized, intense, mid-infrared laser field with special attention to the recently discovered Low Energy Structure (LES)  whose origin is not yet fully understood. In this paper we will go deeper in the analysis of the LES by studying its angular distribution and examine its behavior in circularly polarized light.
Catoire, F, Blaga, C. I, Sistrunk, E, Muller, H. G, Agostini, Pierre, & DiMauro, L. F. (2009). Mid-infrared strong field ionization angular distributions. Laser Phys., 19, 1574–1580. doi:10.1134/s1054660x09150079