[1] Joannopoulos J D, Villeneuve P R, Fan S. Photonic crystals: putting new twist on light. Nature, 1997, 386(6621): 143–149
[2] Knight J C, Broeng J, Birks T A, Russell P S J. Photonic band gap guidance in optical fibers. Science, 1998, 282(5393): 1476–1478
[3] Barnes W L, Dereux A, Ebbesen T W. Surface plasmon subwavelength optics. Nature, 2003, 424(6950): 824–830
[4] Shelby R A, Smith D R, Schultz S. Experimental verification of a negative index of refraction. Science, 2001, 292(5514): 77–79
[5] Marani R, D’Orazio A, Petruzzelli V, Rodrigo S G, Martin-Moreno L, Garcia-Vidal F J, Bravo-Abad J. Gain-assisted extraordinary optical transmission through periodic arrays of subwavelength apertures. New Journal of Physics, 2012, 14(1): 013020
[6] Feng L, Xu Y L, FegadolliWS, LuMH, Oliveira J E, Almeida V R, Chen Y F, Scherer A. Experimental demonstration of a unidirectional reflectionless parity-time metamaterial at optical frequencies. Nature Materials, 2013, 12(2): 108–113
[7] Rüter C E, Makris K G, El-Ganainy R, Christodoulides D N, Segev M, Kip D. Observation of parity–time symmetry in optics. Nature Physics, 2010, 6(3): 192–195
[8] Mostafazadeh A. Spectral singularities of complex scattering potentials and infinite reflection and transmission coefficients at real energies. Physical Review Letters, 2009, 102(22): 220402
[9] uo A, Salamo G J, Duchesne D, Morandotti R, Volatier-Ravat M, Aimez V, Siviloglou G A, Christodoulides D N. Observation of PTsymmetry breaking in complex optical potentials. Physical Review Letters, 2009, 103(9): 093902
[10] Longhi S. PT-symmetric laser absorber. Physical Review A, 2010, 82(3): 031801
[11] Chong Y D, Ge L, Stone A D. PT-symmetry breaking and laserabsorber modes in optical scattering systems. Physical Review Letters, 2011, 106(9): 093902
[12] Ge L, Chong Y D, Rotter S, Tureci H E, Stone A D. Unconventional modes in lasers with spatially varying gain and loss. Physical Review A, 2011, 84(2): 023820
[13] Nazari F, Nazari M, Moravvej-Farshi M K. A 22 spatial optical switch based on PT-symmetry. Optics Letters, 2011, 36(22): 4368– 4370
[14] Bender N, Factor S, Bodyfelt J D, Ramezani H, Christodoulides D N, Ellis F M, Kottos T. Observation of asymmetric transport in structures with active nonlinearities. Physical Review Letters, 2013, 110(23): 234101
[15] Nazari F, Bender N, Ramezani H, Moravvej-Farshi M K, Christodoulides D N, Kottos T. Optical isolation via PT-symmetric nonlinear Fano resonances. Optics Express, 2014, 22(8): 9574– 9584
[16] Peng B, ?zdemir S K, Lei F, Monifi F, Gianfreda M, Long G L, Fan S H, Nori F, Bender C M, Yang L. Parity-time-symmetric whispering-gallery microcavities. Nature Physics, 2014, 10(5): 394–398
[17] Lin Z, Ramezani H, Eichelkraut T, Kottos T, Cao H, Christodoulides D N. Unidirectional invisibility induced by PT-symmetric periodic structures. Physical Review Letters, 2011, 106(21): 213901
[18] Longhi S. Invisibility in PT-symmetric complex crystals. Journal of Physics A, Mathematical and Theoretical, 2011, 44(48): 485302
[19] Zhu X F, Peng Y G, Zhao D G. Anisotropic reflection oscillation in periodic multilayer structures of parity-time symmetry. Optics Express, 2014, 22(15): 18401–18411
[20] Ding S, Wang G P. Extraordinary reflection and transmission with direction dependent wavelength selectivity based on parity-timesymmetric multilayers. Journal of Applied Physics, 2015, 117(2): 023104
[21] Born M, Wolf E. Principles of Optics: Electromagnetic Theory of Propagation, Interference and Diffraction of Light. Elsevier, Cambridge University, 1997
[22] Ge L, Chong Y D, Stone A D. Conservation relations and anisotropic transmission resonances in one-dimensional PT-symmetric photonic heterostructures. Physical Review A, 2012, 85(2): 023802
[23] Schomerus H. Quantum noise and self-sustained radiation of PTsymmetric systems. Physical Review Letters, 2010, 104(23): 233601 === Yingxin Jiang obtained her master’s degree from Lanzhou University, Lanzhou (China), in 2006. In 1999, as a teacher she joined the Department of Physics, Jiangsu University, Zhenjiang, China. In 2012, she was elected as an associate professor. Her research interests include optical physics