The 80th JSAP Autumn Meeting 2019

Presentation information

Oral presentation

4 JSAP-OSA Joint Symposia 2019 » 4.5 Terahertz Photonics

[19p-E215-1~17] 4.5 Terahertz Photonics

Thu. Sep 19, 2019 12:45 PM - 6:30 PM E215 (E215)

Toshihiko Kiwa(Okayama Univ.), Katsuhiko Miyamoto(Chiba Univ.), Makoto Nakajima(Osaka Univ.)

1:15 PM - 1:45 PM

[19p-E215-2] [INVITED] Tunable terahertz vortex source based on difference frequency generation

Katsuhiko Miyamoto1,2, Takashige Omatsu1,2 (1.Chiba Univ., 2.MCRC Chiba Univ.)

Keywords:optical vortex, terahertz, difference frequency generation

An optical vortex carries an annular intensity profile and an orbital angular momentum, characterized by a topological charge ℓ, owing to its helical wavefront, and it provides us a variety of potential research opportunities, including chiral fabrications, high-speed communications and scanning microscopes with a spatial resolution beyond the diffraction limit. The above-mentioned applications require strongly frequency versatility of the vortex light sources, thus, a THz vortex source will offer entirely new fundamental sciences and advanced technologies for THz photonics.
To date, we have successfully developed THz vortex sources by employing a Tsurupica vortex phase plate (VPP). However, the VPP is typically designed for a specific frequency, and it inherently constrains the frequency versatility of THz vortex sources.
In this presentation, we propose a novel THz vortex source based on a difference frequency generator (DFG) formed of a 4’-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST) crystal. This system exhibited an extremely wide tunability in a frequency range of 2-6 THz.