Abstract-Terahertz reflectarray as a polarizing beam splitter

Tiaoming Niu, Withawat Withayachumnankul, Aditi Upadhyay, Philipp Gutruf, Derek Abbott, Madhu Bhaskaran, Sharath Sriram, and Christophe Fumeaux  »View Author Affiliations

http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-22-13-16148

Optics Express, Vol. 22, Issue 13, pp. 16148-16160 (2014)
http://dx.doi.org/10.1364/OE.22.016148

A reflectarray is designed and demonstrated experimentally for polarization-dependent beam splitting at 1 THz. This reflective component is composed of two sets of orthogonal strip dipoles arranged into interlaced triangular lattices over a ground plane. By varying the length and width of the dipoles a polarization-dependent localized phase change is achieved on reflection, allowing periodic subarrays with a desired progressive phase distribution. Both the simulated field distributions and the measurement results from a fabricated sample verify the validity of the proposed concept. The designed terahertz reflectarray can efficiently separate the two polarization components of a normally incident wave towards different predesigned directions of ±30°. Furthermore, the measured radiation patterns show excellent polarization purity, with a cross-polarization level below −27 dB. The designed reflectarray could be applied as a polarizing beam splitter for polarization-sensitive terahertz imaging or for emerging terahertz communications.

© 2014 Optical Society of America