Spatial-temporal dynamics of broadband terahertz Bessel beam propagation

International Conference of Young Scientists and Specialists "Optics-2015"

Semenova, V.A.^1 ; Kulya, M.S.^1 ; Bespalov, V.G.^1

ITMO University, Department of Photonics and Optoinformatics, 3/2B Kadetskaya line, Saint Petersburg, Russia^1

关键词: Broadband terahertz;    Dispersive medium;    Resolution enhancement;    Scalar diffraction theory;    Spatial amplitude;    Spatial temporals;    Spectral components;    Terahertz imaging;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/735/1/012063/pdf
DOI  :  10.1088/1742-6596/735/1/012063

来源: IOP

【 摘 要 】

The unique properties of narrowband and broadband terahertz Bessel beams have led to a number of their applications in different fields, for example, for the depth of focusing and resolution enhancement in terahertz imaging. However, broadband terahertz Bessel beams can probably be also used for the diffraction minimization in the short-range broadband terahertz communications. For this purpose, the study of spatial-temporal dynamics of the broadband terahertz Bessel beams is needed. Here we present a simulation-based study of the propagating in non-dispersive medium broadband Bessel beams generated by a conical axicon lens. The algorithm based on scalar diffraction theory was used to obtain the spatial amplitude and phase distributions of the Bessel beam in the frequency range from 0.1 to 3 THz at the distances 10-200 mm from the axicon. Bessel beam field is studied for the different spectral components of the initial pulse. The simulation results show that for the given parameters of the axicon lens one can obtain the Gauss-Bessel beam generation in the spectral range from 0.1 to 3 THz. The length of non-diffraction propagation for a different spectral components was measured, and it was shown that for all spectral components of the initial pulse this length is about 130 mm.