Highly multimodal structure of high topological charge extreme ultraviolet vortex beams

Abstract

Optical beams carrying orbital angular momentum are a very active field of research for their prospective applications, especially at short wavelengths. We consider here such beams produced through high-harmonic generation (HHG) in a rare gas and analyze the characterization of their high-charge vortex structure by an extreme ultraviolet Hartmann wavefront sensor. We show that such HHG beams are generally composed of a set of numerous vortex modes. The sensitivity of the intensity and phase of the HHG beam to the infrared laser aberrations is investigated using a deformable mirror.

Single-shot wavefront characterization of high topological charge extreme-ultraviolet vortex

“…In contrast to diffractive [10] or interferometric techniques [5], using a wavefront sensor yields a complete amplitude and phase of the vortex beam. It is also to note that wavefront measurements of optical vortices have previously been used to measure the Poynting vector skew angle [11], and most recently, revealed the multimodal nature of EUV vortices obtained through HHG in a noble gas [12].…”

Design of Pauci-Adaptive, Spirally Tiled Mirrors for Large Size Optical Vortex Generation

“…A typical twolobe shape can then be observed, oriented at 45 • from the axis of astigmatism. This has potentially severe consequences, especially when the physical process taking place at focus has a non linear dependence with intensity [18], [19].…”

Solid-target seeded soft X-ray laser for short pulses and optical vortex amplification

“…With the know-how of seeded-XRL operation [13,15], and EUV-vortex wavefront metrology [11,12], we recently attempted to inject high-charge EUV vortex in X-ray laser plasma. The primary interest is to answer the following fundamental question: does OAM carried by the vortex seed gets transferred to the amplified beam?…”

“…This issue can particularly be critical for the amplification of helically-phased vortex beams. Recent progress in soft X-ray wavefront metrology finally has permitted amplitude, phase, and modal content characterization of EUV vortices obtained through HH generation in rare gas [8,[11][12]. Therefore, it is now possible to investigate whether the OAM carried by optical vortices is conserved during the amplification in XRL-plasma.…”