title: Fano resonances from gradient-index metamaterials.
abstract: Fano resonances - resonant scattering features with a characteristic asymmetric profile - have generated much interest, due to their extensive and valuable applications in chemical or biological sensors, new types of optical switches, lasers and nonlinear optics. They have been observed in a wide variety of resonant optical systems, including photonic crystals, metamaterials, metallic gratings and nanostructures. In this work, a waveguide structure is designed by employing gradient-index metamaterials, supporting strong Fano resonances with extremely sharp spectra. As the changes in the transmission spectrum originate from the interaction of guided modes from different channels, instead of resonance structures or metamolecules, the Fano resonances can be observed for both transverse electric and transverse magnetic polarizations. These findings are verified by fine agreement with analytical calculations and experimental results at microwave, as well as simulated results at near infrared frequencies.
authors.affiliation: College of Physics, Optoelectronics and Energy &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, No. 1 Shizi Street, Suzhou 215006, China.
authors.forename: Yadong
authors.initials: Y
authors.lastname: Xu
authors.affiliation: College of Physics, Optoelectronics and Energy &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, No. 1 Shizi Street, Suzhou 215006, China.
authors.forename: Sucheng
authors.initials: S
authors.lastname: Li
authors.affiliation: College of Physics, Optoelectronics and Energy &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, No. 1 Shizi Street, Suzhou 215006, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Hou
authors.affiliation: College of Physics, Optoelectronics and Energy &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, No. 1 Shizi Street, Suzhou 215006, China.
authors.forename: Huanyang
authors.initials: H
authors.lastname: Chen
references.citation: Science. 2015 Mar 20;347(6228):1342-5
references.pmid: 25700175
references.citation: Nano Lett. 2012 Sep 12;12(9):4932-6
references.pmid: 22894542
references.citation: Opt Express. 2012 Jul 2;20(14):15882-90
references.pmid: 22772278
references.citation: Science. 2001 Apr 6;292(5514):77-9
references.pmid: 11292865
references.citation: Nat Commun. 2014 Dec 16;5:5753
references.pmid: 25511508
references.citation: Phys Rev Lett. 2014 Aug 29;113(9):093901
references.pmid: 25215984
references.citation: Nat Commun. 2014 May 27;5:3892
references.pmid: 24861488
references.citation: Nat Mater. 2010 Sep;9(9):707-15
references.pmid: 20733610
references.citation: Science. 2006 Nov 10;314(5801):977-80
references.pmid: 17053110
references.citation: Phys Rev Lett. 2013 May 10;110(19):197401
references.pmid: 23705738
references.citation: Nat Mater. 2010 May;9(5):387-96
references.pmid: 20414221
references.citation: Phys Rev Lett. 2000 Oct 30;85(18):3966-9
references.pmid: 11041972
references.citation: Science. 2014 Jul 18;345(6194):298-302
references.pmid: 25035488
references.citation: Phys Rev Lett. 2007 Oct 5;99(14):147401
references.pmid: 17930720
references.citation: Nature. 2014 Jul 3;511(7507):65-9
references.pmid: 24990746
references.citation: Science. 2006 Jun 23;312(5781):1777-80
references.pmid: 16728596
references.citation: Phys Rev Lett. 2013 May 17;110(20):203903
references.pmid: 25167411
references.citation: Nat Mater. 2014 May;13(5):471-5
references.pmid: 24747781
references.citation: Science. 2011 Oct 21;334(6054):333-7
references.pmid: 21885733
references.citation: Science. 2013 Apr 19;340(6130):331-4
references.pmid: 23599488
references.citation: Science. 2006 Jun 23;312(5781):1780-2
references.pmid: 16728597
references.citation: Science. 2013 Mar 22;339(6126):1405-7
references.pmid: 23520105
references.citation: Nat Commun. 2013;4:2561
references.pmid: 24096709
references.citation: Nat Nanotechnol. 2013 Feb;8(2):95-9
references.pmid: 23353675
references.citation: Nat Mater. 2012 Apr 01;11(5):426-31
references.pmid: 22466746
references.citation: Science. 2012 Jan 27;335(6067):427
references.pmid: 22194414
references.citation: Nature. 2008 Sep 18;455(7211):376-9
references.pmid: 18690249