Design of broadband terahertz vector and vortex beams: I. Review of materials and components

Abstract

In this paper, we review the existing approaches for vortex and vector beam shaping and generation in the terahertz frequency range. The particular focus of this review is on the possibility of homogeneous topological charge formation in the ultra-wide spectral interval inherent to ultrashort terahertz pulses. We review the available materials and components, analyse proposed and potentially possible solutions for broadband terahertz vortex and vector beam shaping, compare all developed approaches, and put forward a unified concept for constructing passive shapers of such beams from the existing component base.

Keywords

• terahertz radiation
• vortex beams
• vector beams
• achromatic wave plates
• broadband terahertz radiation
• digital holography
• terahertz holography
• total internal reflection
• metasurface
• thz liquid crystals
• geometric phase