3D-Printed Broadband Dielectric Tube Terahertz Waveguide with Anti-Reflection Structure
We demonstrate broadband, low loss, and close-to-zero dispersion guidance of terahertz (THz) radiation in a dielectric tube with an anti-reflection structure (AR-tube waveguide) in the frequency range from 0.2 to 1.0 THz. The anti-reflection structure (ARS) consists of close-packed cones in a hexagonal lattice arranged on the outer surface of the tube cladding. The feature size of the ARS is in the order of the wavelength between 0.2 and 1.0 THz. The waveguides are fabricated with the versatile and cost efficient 3D-printing method. Terahertz time-domain spectroscopy (THz-TDS) measurements as well as 3D finite-difference time-domain simulations (FDTD) are performed to extensively characterize the AR-tube waveguides. Spectrograms, attenuation spectra, effective phase refractive indices, and the group-velocity dispersion parameters β2 of the AR-tube waveguides are presented. Both the experimental and numerical results confirm the extended bandwidth and smaller group-velocity dispersion of the AR-tube waveguide compared to a low loss plain dielectric tube THz waveguide. The AR-tube waveguide prototypes show an attenuation spectrum close to the theoretical limit given by the infinite cladding tube waveguide.
KeywordsTerahertz Waveguide 3D-printing Terahertz spectroscopy
- 1.M. Tonouchi, Nat. Photonics 1 (2007), no. 2, 97.Google Scholar
- 2.S. Atakaramians, S. Afshar V, T.M. Monro, and D. Abbott, Adv. Opt. Photonics 5 (2013), no. 2, 169.Google Scholar
- 3.D. Chen and H. Chen, Opt. Express 18 (2010), no. 4, 3762.Google Scholar
- 4.H. Bao, K. Nielsen, O. Bang, and P.U. Jepsen, Sci. Rep. 5 (2015), 7620.Google Scholar
- 5.D.W. Vogt, J. Anthony, and R. Leonhardt, Opt. Express 23 (2015), no. 26, 33359.Google Scholar
- 6.D.L. Brundrett, E.N. Glytsis, and T.K. Gaylord, Appl. Optics 33 (1994), no. 13, 2695.Google Scholar
- 7.S.F. Busch, M. Weidenbach, M. Fey, F. Schfer, T. Probst, and M. Koch, J. Infrared Millim. Te. 35 (2014), no. 12, 993.Google Scholar
- 8.A.D. Squires, E. Constable, and R.A. Lewis, J. Infrared Millim. Te. 36 (2014), no. 1, 72.Google Scholar
- 9.S.F. Busch, M. Weidenbach, J.C. Balzer, and M. Koch, J. Infrared Millim. Te. 37 (2015), no. 4, 303.Google Scholar
- 10.N. Yudasari, J. Anthony, and R. Leonhardt, Opt. Express 22 (2014), no. 21, 26042.Google Scholar
- 11.3d systems http://www.3dsystems.com.
- 12.A.F. Oskooi, D. Roundy, M. Ibanescu, P. Bermel, J. Joannopoulos, and S.G. Johnson, Comput. Phys. Commun. 181 (2010), no. 3, 687.Google Scholar
- 13.Y.H. Lo and R. Leonhardt, Opt. Express 16 (2008), no. 20, 15991.Google Scholar