Abstract-Terahertz filter integrated with a subwavelength structured antireflection coating

Jeong Min Woo¹, Dae-Seon Kim¹, Dong-Ju Kim¹ and Jae-Hyung Jang^1,a)
http://scitation.aip.org/content/aip/journal/adva/5/12/10.1063/1.4939571
a) Electronic mail: jjang@gist.ac.kr.
AIP Advances 5, 127238 (2015); http://dx.doi.org/10.1063/1.4939571

Micro-pyramid shaped subwavelength structures (SWSs) were integrated on both sides of a terahertz (THz) filter by means of stamping methods. Two silicon-based stamping molds fabricated via crystallographic wet etching were utilized to replicate SWSs onto cyclo-olefin copolymer (COC) films coated onto both sides of a THz filter at the same time. The SWSs act as an broadband antireflection coating to reduce the surfacereflection loss in a frequency range of 0.2 THz to 1.4 THz. Compared to a THz filter without SWSs, the filter integrated with double-sided SWSs exhibits a low standing wave ratio inside the substrate and THz signal transmission enhancement of up to 10.8%.

Abstract-Broadband terahertz absorber realized by self-assembled multilayer glass spheres

http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-20-12-13566


Dae-Seon Kim, Dong-Hyun Kim, Sehyun Hwang, and Jae Hyung jang

A broadband terahertz (THz) absorber consisting of multilayer glass spheres and polydimethylsiloxane (PDMS) was realized. The multilayer glass spheres were deposited by repeating a self-assembly method used to form monolayer glass spheres and by the spin-coating of PDMS to fill the gaps between the glass spheres. The average reflection at the surface of the absorber was 0.8% and the absorbance was higher than 98% in the frequency range between 0.7 to 2.0 THz.

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