Research output: Contribution to journal › Article › peer-review
Experimental Realization of an Epsilon-Near-Zero Graded-Index Metalens at Terahertz Frequencies. / Pacheco-Peña, Victor; Engheta, Nader; Kuznetsov, Sergei et al.
In: Physical Review Applied, Vol. 8, No. 3, 034036, 29.09.2017.Research output: Contribution to journal › Article › peer-review
}
TY - JOUR
T1 - Experimental Realization of an Epsilon-Near-Zero Graded-Index Metalens at Terahertz Frequencies
AU - Pacheco-Peña, Victor
AU - Engheta, Nader
AU - Kuznetsov, Sergei
AU - Gentselev, Alexandr
AU - Beruete, Miguel
PY - 2017/9/29
Y1 - 2017/9/29
N2 - The terahertz band has been historically hindered by the lack of efficient generators and detectors, but a series of recent breakthroughs have helped to effectively close the "terahertz gap." A rapid development of terahertz technology has been possible thanks to the translation of revolutionary concepts from other regions of the electromagnetic spectrum. Among them, metamaterials stand out for their unprecedented ability to control wave propagation and manipulate electromagnetic response of matter. They have become a workhorse in the development of terahertz devices such as lenses, polarizers, etc., with fascinating features. In particular, epsilon-near-zero (ENZ) metamaterials have attracted much attention in the past several years due to their unusual properties such as squeezing, tunneling, and supercoupling where a wave traveling inside an electrically small channel filled with an ENZ medium can be tunneled through it, reducing reflections and coupling most of its energy. Here, we design and experimentally demonstrate an ENZ graded-index (GRIN) metamaterial lens operating at terahertz with a power enhancement of 16.2 dB, using an array of narrow hollow rectangular waveguides working near their cutoff frequencies. This is a demonstration of an ENZ GRIN device at terahertz and can open the path towards other realizations of similar devices enabling full quasioptical processing of terahertz signals.
AB - The terahertz band has been historically hindered by the lack of efficient generators and detectors, but a series of recent breakthroughs have helped to effectively close the "terahertz gap." A rapid development of terahertz technology has been possible thanks to the translation of revolutionary concepts from other regions of the electromagnetic spectrum. Among them, metamaterials stand out for their unprecedented ability to control wave propagation and manipulate electromagnetic response of matter. They have become a workhorse in the development of terahertz devices such as lenses, polarizers, etc., with fascinating features. In particular, epsilon-near-zero (ENZ) metamaterials have attracted much attention in the past several years due to their unusual properties such as squeezing, tunneling, and supercoupling where a wave traveling inside an electrically small channel filled with an ENZ medium can be tunneled through it, reducing reflections and coupling most of its energy. Here, we design and experimentally demonstrate an ENZ graded-index (GRIN) metamaterial lens operating at terahertz with a power enhancement of 16.2 dB, using an array of narrow hollow rectangular waveguides working near their cutoff frequencies. This is a demonstration of an ENZ GRIN device at terahertz and can open the path towards other realizations of similar devices enabling full quasioptical processing of terahertz signals.
KW - NEGATIVE INDEX
KW - WAVE-GUIDE
KW - METAMATERIALS
KW - LENS
KW - SUBTERAHERTZ
KW - WAVELENGTHS
KW - TECHNOLOGY
KW - REFRACTION
KW - CHANNELS
KW - DEVICES
UR - http://www.scopus.com/inward/record.url?scp=85030696622&partnerID=8YFLogxK
U2 - 10.1103/PhysRevApplied.8.034036
DO - 10.1103/PhysRevApplied.8.034036
M3 - Article
AN - SCOPUS:85030696622
VL - 8
JO - Physical Review Applied
JF - Physical Review Applied
SN - 2331-7019
IS - 3
M1 - 034036
ER -
ID: 8678886