1. Generation of terahertz vortex pulses without any need of manipulation in the terahertz region
- Author
-
Yi Cai, Qiying Song, Xinjian Pan, Ying Li, Shixiang Xu, Shuiqin Zheng, Xuanke Zeng, Qinggang Lin, Lang Zha, and Zhenkuan Chen
- Subjects
Diffraction ,Materials science ,Field (physics) ,business.industry ,Terahertz radiation ,Physics::Optics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Vortex ,010309 optics ,Optics ,Pulse pair ,0103 physical sciences ,Vortex beam ,0210 nano-technology ,business ,Phase modulation ,Optical vortex - Abstract
Converting a Gaussian mode to a vortex beam is much more inconvenient in the terahertz (THz) region than in the near-infrared (NIR) region due to underdevelopment of THz components and strong THz diffraction. This Letter reports the direct generation of THz vortex pulses by optical difference-frequency between two NIR chirped pulses with different topological charges (TCs). By designing a passive and transmissive device for a collinear NIR pulse pair with conjugated TCs, we have experimentally obtained stable THz vortex pulses with a TC value of 2 or -2. The process needs no THz components and so is flexible to be realized and has promising applications in the THz field.
- Published
- 2019