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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 18, Iss. 26 — Dec. 20, 2010
  • pp: 27748–27757

Metamaterial-based gradient index lens with strong focusing in the THz frequency range

J. Neu, B. Krolla, O. Paul, B. Reinhard, R. Beigang, and M. Rahm  »View Author Affiliations

Optics Express, Vol. 18, Issue 26, pp. 27748-27757 (2010)

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The development of innovative terahertz (THz) imaging systems has recently moved in the focus of scientific efforts due to the ability to screen substances through textiles or plastics. The invention of THz imaging systems with high spatial resolution is of increasing interest for applications in the realms of quality control, spectroscopy in dusty environment and security inspections. To realize compact THz imaging systems with high spatial resolution it is necessary to develop lenses of minimized thickness that still allow one to focus THz radiation to small spot diameters with low optical aberrations. In addition, it would be desirable if the lenses offered adaptive control of their optical properties to optimize the performance of the imaging systems in the context of different applications. Here we present the design, fabrication and the measurement of the optical properties of spectrally broadband metamaterial-based gradient index (GRIN) lenses that allow one to focus THz radiation to a spot diameter of approximately one wavelength. Due to the subwavelength thickness and the high focusing strength the presented GRIN lenses are an important step towards compact THz imaging systems with high spatial resolution. Furthermore, the results open the path to a new class of adaptive THz optics by extension of the concept to tunable metamaterials.

© 2010 Optical Society of America

OCIS Codes
(080.3620) Geometric optics : Lens system design
(160.4670) Materials : Optical materials
(160.3918) Materials : Metamaterials
(300.6495) Spectroscopy : Spectroscopy, teraherz
(110.6795) Imaging systems : Terahertz imaging
(240.3990) Optics at surfaces : Micro-optical devices

ToC Category:

Original Manuscript: October 28, 2010
Revised Manuscript: December 10, 2010
Manuscript Accepted: December 10, 2010
Published: December 16, 2010

J. Neu, B. Krolla, O. Paul, B. Reinhard, R. Beigang, and M. Rahm, "Metamaterial-based gradient index lens with strong focusing in the THz frequency range," Opt. Express 18, 27748-27757 (2010)

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