• Photonics Insights
  • Vol. 4, Issue 1, R02 (2025)
Shaohua Dong1,†, Heng Wei2, Zhipeng Li2, Guangtao Cao3..., Kun Xue1, Yang Chen4,* and Cheng-Wei Qiu2,*|Show fewer author(s)
Author Affiliations
  • 1Peng Cheng Laboratory, Shenzhen, China
  • 2Department of Electrical and Computer Engineering, National University of Singapore, Singapore
  • 3School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha, China
  • 4Chinese Academy of Sciences Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, China
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    DOI: 10.3788/PI.2025.R02 Cite this Article Set citation alerts
    Shaohua Dong, Heng Wei, Zhipeng Li, Guangtao Cao, Kun Xue, Yang Chen, Cheng-Wei Qiu, "Exceptional-point optics with loss engineering," Photon. Insights 4, R02 (2025) Copy Citation Text show less
    References

    [1] R. Bogue. Detecting gases with light: a review of optical gas sensor technologies. Sensor Rev., 35, 133(2015). https://doi.org/10.1108/SR-09-2014-696

    [2] R. S. El Shamy, D. Khalil, M. A. Swillam. mid infrared optical gas sensor using plasmonic Mach-Zehnder interferometer. Sci. Rep., 10, 1293(2020). https://doi.org/10.1038/s41598-020-57538-1

    [3] N. Khansili, G. Rattu, P. M. Krishna. Label-free optical biosensors for food and biological sensor applications. Sens. Actuators B, 265, 35(2018). https://doi.org/10.1016/j.snb.2018.03.004

    [4] J.-H. Park et al. Symmetry-breaking-induced plasmonic exceptional points and nanoscale sensing. Nat. Phys., 16, 462(2020). https://doi.org/10.1038/s41567-020-0796-x

    [5] Y. Xu et al. Optical refractive index sensors with plasmonic and photonic structures: promising and inconvenient truth. Adv. Opt. Mater., 7, 1801433(2019). https://doi.org/10.1002/adom.201801433

    [6] W. B. Ji et al. Ultrahigh sensitivity refractive index sensor based on optical microfiber. IEEE Photon. Technol. Lett., 24, 1872(2012). https://doi.org/10.1109/LPT.2012.2217738

    [7] M. P. Hokmabadi et al. Non-Hermitian ring laser gyroscopes with enhanced Sagnac sensitivity. Nature, 576, 70(2019). https://doi.org/10.1038/s41586-019-1780-4

    [8] L. Tong. Micro/nanofibre optical sensors: challenges and prospects. Sensors, 18, 903(2018). https://doi.org/10.3390/s18030903

    [9] P. M. Tracey. Intrinsic fiber-optic sensors. IEEE Trans. Ind. Appl., 27, 96(1991). https://doi.org/10.1109/28.67537

    [10] Jun Yang, L. J. Guo. Optical sensors based on active microcavities. IEEE J. Sel. Top. Quantum Electron., 12, 143(2006). https://doi.org/10.1109/JSTQE.2005.862953

    [11] B. J. Thibeault et al. Reduced optical scattering loss in vertical-cavity lasers using a thin (300/spl Aring/) oxide aperture. IEEE Photon. Technol. Lett., 8, 593(1996). https://doi.org/10.1109/68.491549

    [12] N. A. Pikhtin et al. Internal optical loss in semiconductor lasers. Semiconductors, 38, 360(2004). https://doi.org/10.1134/1.1682615

    [13] M. T. Hill, M. C. Gather. Advances in small lasers. Nat. Photon., 8, 908(2014). https://doi.org/10.1038/nphoton.2014.239

    [14] J. L. O’Brien. Optical quantum computing. Science, 318, 1567(2007). https://doi.org/10.1126/science.1142892

    [15] P. Kok et al. Linear optical quantum computing with photonic qubits. Rev. Mod. Phys., 79, 135(2007). https://doi.org/10.1103/RevModPhys.79.135

    [16] Z. Li et al. Non-Hermitian electromagnetic metasurfaces at exceptional points. Prog. Electromagn. Res., 171, 1(2021). http://10.2528/pier21051703

    [17] C. M. Bender, S. Boettcher. Real spectra in Non-Hermitian Hamiltonians having P T symmetry. Phys. Rev. Lett., 80, 5243(1998). https://doi.org/10.1103/PhysRevLett.80.5243

    [18] M.-A. Miri, A. Alù. Exceptional points in optics and photonics. Science, 363, eaar7709(2019). https://doi.org/10.1126/science.aar7709

    [19] A. Li et al. Exceptional points and non-Hermitian photonics at the nanoscale. Nat. Nanotechnol., 18, 706(2023). https://doi.org/10.1038/s41565-023-01408-0

    [20] X.-L. Zhang. Dynamically encircling an exceptional point in anti-parity-time symmetric systems: asymmetric mode switching for symmetry-broken modes. Light Sci. Appl., 8, 88(2019). https://doi.org/10.1038/s41377-019-0200-8

    [21] C. Dembowski et al. Experimental observation of the topological structure of exceptional points. Phys. Rev. Lett., 86, 787(2001). https://doi.org/10.1103/PhysRevLett.86.787

    [22] Ş. K. Özdemir et al. Parity–time symmetry and exceptional points in photonics. Nat. Mater., 18, 783(2019). https://doi.org/10.1038/s41563-019-0304-9

    [23] H. Zhao, L. Feng. Parity–time symmetric photonics. Natl. Sci. Rev., 5, 183(2018). https://doi.org/10.1093/nsr/nwy011

    [24] C. E. Rüter et al. Observation of parity-time symmetry in optics. Nature Phys., 6, 192(2010). https://doi.org/10.1038/nphys1515

    [25] Q. Zhong et al. Sensing with exceptional surfaces in order to combine sensitivity with robustness. Phys. Rev. Lett., 122, 153902(2019). https://doi.org/10.1103/PhysRevLett.122.153902

    [26] H.-K. Lau, A. A. Clerk. Fundamental limits and non-reciprocal approaches in non-Hermitian quantum sensing. Nat. Commun., 9, 4320(2018). https://doi.org/10.1038/s41467-018-06477-7

    [27] D. F. Siriani, P. O. Leisher, K. D. Choquette. Loss-induced confinement in photonic crystal vertical-cavity surface-emitting lasers. IEEE J. Quantum Electron., 45, 762(2009). https://doi.org/10.1109/JQE.2009.2013124

    [28] H. Zhang et al. Loss-induced transparency in optomechanics. Opt. Express, 26, 25199(2018). https://doi.org/10.1364/OE.26.025199

    [29] X. Huang et al. Loss-induced nonreciprocity. Light Sci. Appl., 10, 30(2021). https://doi.org/10.1038/s41377-021-00464-2

    [30] S. Dong et al. Loss-assisted metasurface at an exceptional point. ACS Photonics, 7, 3321(2020). https://doi.org/10.1021/acsphotonics.0c01440

    [31] H. A. Haus, W. Huang. Coupled-mode theory. Proc. IEEE, 79, 1505(1991). https://doi.org/10.1109/5.104225

    [32] J. Wiersig. Review of exceptional point-based sensors. Photon. Res., 8, 1457(2020). https://doi.org/10.1364/PRJ.396115

    [33] J. Wiersig. Robustness of exceptional-point-based sensors against parametric noise: The role of Hamiltonian and Liouvillian degeneracies. Phys. Rev. A, 101, 053846(2020). https://doi.org/10.1103/PhysRevA.101.053846

    [34] S. Taravati, G. V. Eleftheriades. Full-duplex reflective beamsteering metasurface featuring magnetless nonreciprocal amplification. Nat. Commun., 12, 4414(2021). https://doi.org/10.1038/s41467-021-24749-7

    [35] A. Guo et al. Observation of P T -symmetry breaking in complex optical potentials. Phys. Rev. Lett., 103, 093902(2009). https://doi.org/10.1103/PhysRevLett.103.093902

    [36] M. Ornigotti, A. Szameit. Quasi PT-symmetry in passive photonic lattices. J. Opt., 16, 065501(2014). https://doi.org/10.1088/2040-8978/16/6/065501

    [37] X. Liu et al. High-Q tunable microwave cavity resonators and filters using SOI-based RF MEMS tuners. J. Microelectromech. Syst., 19, 774(2010). https://doi.org/10.1109/JMEMS.2010.2055544

    [38] S. Messelot et al. Tamm cavity in the terahertz spectral range. ACS Photonics, 7, 2906(2020). https://doi.org/10.1021/acsphotonics.0c01254

    [39] A. K. Bhowmik. Polygonal optical cavities. Appl. Opt., 39, 3071(2000). https://doi.org/10.1364/AO.39.003071

    [40] C. Wang et al. Coherent perfect absorption at an exceptional point. Science, 373, 1261(2021). https://doi.org/10.1126/science.abj1028

    [41] S. Soleymani et al. Chiral and degenerate perfect absorption on exceptional surfaces. Nat. Commun., 13, 599(2022). https://doi.org/10.1038/s41467-022-27990-w

    [42] G.-Q. Zhang, Y. Wang, W. Xiong. Detection sensitivity enhancement of magnon Kerr nonlinearity in cavity magnonics induced by coherent perfect absorption. Phys. Rev. B, 107, 064417(2023). https://doi.org/10.1103/PhysRevB.107.064417

    [43] W. R. Sweeney et al. Perfectly absorbing exceptional points and chiral absorbers. Phys. Rev. Lett., 122, 093901(2019). https://doi.org/10.1103/PhysRevLett.122.093901

    [44] C. Ferise et al. Exceptional points of P T -symmetric reflectionless states in complex scattering systems. Phys. Rev. Lett., 128, 203904(2022). https://doi.org/10.1103/PhysRevLett.128.203904

    [45] Y. Zuo et al. Loss-induced suppression, revival, and switch of photon blockade. Phys. Rev. A, 106, 043715(2022). https://doi.org/10.1103/PhysRevA.106.043715

    [46] C. Wang et al. Electromagnetically induced transparency at a chiral exceptional point. Nat. Phys., 16, 334(2020). https://doi.org/10.1038/s41567-019-0746-7

    [47] B. Peng et al. Loss-induced suppression and revival of lasing. Science, 346, 328(2014). https://doi.org/10.1126/science.1258004

    [48] W. Chen et al. Exceptional points enhance sensing in an optical microcavity. Nature, 548, 192(2017). https://doi.org/10.1038/nature23281

    [49] M. De Carlo et al. Non-Hermitian sensing in photonics and electronics: a review. Sensors, 22, 3977(2022). https://doi.org/10.3390/s22113977

    [50] J. Wiersig. Sensors operating at exceptional points: general theory. Phys. Rev. A, 93, 033809(2016). https://doi.org/10.1103/PhysRevA.93.033809

    [51] Y. P. Ruan et al. Observation of loss-enhanced magneto-optical effect. Nat. Photonics, 19, 109(2024). https://doi.org/10.1038/s41566-024-01592-y

    [52] A. Metelmann, A. A. Clerk. Nonreciprocal photon transmission and amplification via reservoir engineering. Phys. Rev. X, 5, 021025(2015). https://doi.org/10.1103/PhysRevX.5.021025

    [53] B. Li et al. Loss-induced quantum nonreciprocity. npj Quantum Inf., 10, 75(2024). https://doi.org/10.1038/s41534-024-00870-5

    [54] D. G. Baranov et al. Coherent perfect absorbers: linear control of light with light. Nat. Rev. Mater., 2, 17064(2017). https://doi.org/10.1038/natrevmats.2017.64

    [55] L. Baldacci, S. Zanotto, A. Tredicucci. Coherent perfect absorption in photonic structures. Rend. Fis. Acc. Lincei, 26, 219(2015). https://doi.org/10.1007/s12210-015-0428-z

    [56] Z. Yu, A. Raman, S. Fan. Thermodynamic upper bound on broadband light coupling with photonic structures. Phys. Rev. Lett., 109, 173901(2012). https://doi.org/10.1103/PhysRevLett.109.173901

    [57] Z. Wang et al. Observation of unidirectional backscattering-immune topological electromagnetic states. Nature, 461, 772(2009). https://doi.org/10.1038/nature08293

    [58] Y.-L. Xu et al. Unidirectional transmission based on a passive PT symmetric grating with a nonlinear silicon distributed Bragg reflector cavity. IEEE Photon. J., 6, 1(2014). http://10.1109/JPHOT.2013.2295462

    [59] J. Wiersig. Enhancing the sensitivity of frequency and energy splitting detection by using exceptional points: application to microcavity sensors for single-particle detection. Phys. Rev. Lett., 112, 203901(2014). https://doi.org/10.1103/PhysRevLett.112.203901

    [60] H. Zhang et al. Breaking anti-PT symmetry by spinning a resonator. Nano Lett., 20, 7594(2020). https://doi.org/10.1021/acs.nanolett.0c03119

    [61] W. Li et al. Real frequency splitting indirectly coupled anti-parity-time symmetric nanoparticle sensor. J. Appl. Phys., 128, 134503(2020). https://doi.org/10.1063/5.0020944

    [62] M. D. Carlo et al. Design rules of a microscale PT-symmetric optical gyroscope using group IV platform. J. Lightw. Technol., 36, 3261(2018).

    [63] H. Wang et al. Petermann-factor sensitivity limit near an exceptional point in a Brillouin ring laser gyroscope. Nat. Commun., 11, 1610(2020). https://doi.org/10.1038/s41467-020-15341-6

    [64] Y.-H. Lai et al. Observation of the exceptional-point-enhanced Sagnac effect. Nature, 576, 65(2019). https://doi.org/10.1038/s41586-019-1777-z

    [65] H. Zhao et al. Exceptional point engineered glass slide for microscopic thermal mapping. Nat. Commun., 9, 1764(2018). https://doi.org/10.1038/s41467-018-04251-3

    [66] J. Xu et al. Single-cavity loss-enabled nanometrology. Nat. Nanotechnol., 19, 1472(2024). https://doi.org/10.1038/s41565-024-01729-8

    [67] H. Lee et al. Chiral exceptional point and coherent suppression of backscattering in silicon microring with low loss Mie scatterer. eLight, 3, 20(2023). https://doi.org/10.1186/s43593-023-00043-5

    [68] H. Lee et al. Chiral exceptional point enhanced active tuning and nonreciprocity in micro-resonators. Light Sci. Appl., 14, 45(2025). https://doi.org/10.1038/s41377-024-01686-w

    [69] R. Huang et al. Exceptional photon blockade: engineering photon blockade with chiral exceptional points. Laser Photonics Rev., 16, 2100430(2022). https://doi.org/10.1002/lpor.202100430

    [70] Y.-P. Wang et al. Nonreciprocity and unidirectional invisibility in cavity magnonics. Phys. Rev. Lett., 123, 127202(2019). https://doi.org/10.1103/PhysRevLett.123.127202

    [71] T.-X. Lu et al. Exceptional-point-engineered cavity magnomechanics. Phys. Rev. A, 103, 063708(2021). https://doi.org/10.1103/PhysRevA.103.063708

    [72] D. Zhang et al. Observation of the exceptional point in cavity magnon-polaritons. Nat. Commun., 8, 1368(2017). https://doi.org/10.1038/s41467-017-01634-w

    [73] J. Zhao et al. Phase-controlled pathway interferences and switchable fast-slow light in a cavity-magnon polariton system. Phys. Rev. Appl., 15, 024056(2021). https://doi.org/10.1103/PhysRevApplied.15.024056

    [74] J. Doppler et al. Dynamically encircling an exceptional point for asymmetric mode switching. Nature, 537, 76(2016). https://doi.org/10.1038/nature18605

    [75] J. W. Yoon et al. Time-asymmetric loop around an exceptional point over the full optical communications band. Nature, 562, 86(2018). https://doi.org/10.1038/s41586-018-0523-2

    [76] F. Yu et al. General rules governing the dynamical encircling of an arbitrary number of exceptional points. Phys. Rev. Lett., 127, 253901(2021). https://doi.org/10.1103/PhysRevLett.127.253901

    [77] A. Li et al. Riemann-encircling exceptional points for efficient asymmetric polarization-locked devices. Phys. Rev. Lett., 129, 127401(2022). https://doi.org/10.1103/PhysRevLett.129.127401

    [78] S. N. Ghosh, Y. D. Chong. Exceptional points and asymmetric mode conversion in quasi-guided dual-mode optical waveguides. Sci. Rep., 6, 19837(2016). https://doi.org/10.1038/srep19837

    [79] X. Shu et al. Fast encirclement of an exceptional point for highly efficient and compact chiral mode converters. Nat. Commun., 13, 2123(2022). https://doi.org/10.1038/s41467-022-29777-5

    [80] X. Shu et al. Chiral transmission by an open evolution trajectory in a non-Hermitian system. Light Sci. Appl., 13, 65(2024). https://doi.org/10.1038/s41377-024-01409-1

    [81] Y. Huang et al. Unidirectional reflectionless light propagation at exceptional points. Nanophotonics, 6, 977(2017). https://doi.org/10.1515/nanoph-2017-0019

    [82] X. Yin, X. Zhang. Unidirectional light propagation at exceptional points. Nat. Mater., 12, 175(2013). https://doi.org/10.1038/nmat3576

    [83] Y. Fu et al. Zero index metamaterials with PT symmetry in a waveguide system. Opt. Express, 24, 1648(2016). https://doi.org/10.1364/OE.24.001648

    [84] Z. Lin et al. Unidirectional invisibility induced by PT -symmetric periodic structures. Phys. Rev. Lett., 106, 213901(2011). https://doi.org/10.1103/PhysRevLett.106.213901

    [85] N. X. A. Rivolta, B. Maes. Side-coupled resonators with parity-time symmetry for broadband unidirectional invisibility. Phys. Rev. A, 94, 053854(2016). https://doi.org/10.1103/PhysRevA.94.053854

    [86] C. Hahn et al. Single-mode lasers and parity-time symmetry broken gratings based on active dielectric-loaded long-range surface plasmon polariton waveguides. Opt. Express, 23, 19922(2015). https://doi.org/10.1364/OE.23.019922

    [87] H. Alaeian, J. A. Dionne. Non-Hermitian nanophotonic and plasmonic waveguides. Phys. Rev. B, 89, 075136(2014). https://doi.org/10.1103/PhysRevB.89.075136

    [88] H. Alaeian et al. Towards nanoscale multiplexing with parity-time-symmetric plasmonic coaxial waveguides. Phys. Rev. B, 93, 205439(2016). https://doi.org/10.1103/PhysRevB.93.205439

    [89] W. Wang et al. Unidirectional excitation of radiative-loss-free surface plasmon polaritons in P T -symmetric systems. Phys. Rev. Lett., 119, 077401(2017). https://doi.org/10.1103/PhysRevLett.119.077401

    [90] L. Feng et al. Experimental demonstration of a unidirectional reflectionless parity-time metamaterial at optical frequencies. Nat. Mater., 12, 108(2013). https://doi.org/10.1038/nmat3495

    [91] Y. Xu et al. Subwavelength control of light transport at the exceptional point by non-Hermitian metagratings. Sci. Adv., 9, eadf3510(2023). https://doi.org/10.1126/sciadv.adf3510

    [92] D. Neshev, I. Aharonovich. Optical metasurfaces: new generation building blocks for multi-functional optics. Light Sci. Appl., 7, 58(2018). https://doi.org/10.1038/s41377-018-0058-1

    [93] S. Sun et al. Gradient-index meta-surfaces as a bridge linking propagating waves and surface waves. Nat. Mater., 11, 426(2012). https://doi.org/10.1038/nmat3292

    [94] M. Khorasaninejad et al. Metalenses at visible wavelengths: diffraction-limited focusing and subwavelength resolution imaging. Science, 352, 1190(2016). https://doi.org/10.1126/science.aaf6644

    [95] S. Dong et al. Highly efficient wave-front reshaping of surface waves with dielectric metawalls. Phys. Rev. Appl., 9, 014032(2018). https://doi.org/10.1103/PhysRevApplied.9.014032

    [96] S. Dong et al. On-chip trans-dimensional plasmonic router. Nanophotonics, 9, 3357(2020). https://doi.org/10.1515/nanoph-2020-0078

    [97] S. Li et al. Helicity-delinked manipulations on surface waves and propagating waves by metasurfaces. Nanophotonics, 9, 3473(2020). https://doi.org/10.1515/nanoph-2020-0200

    [98] S. Sun et al. Electromagnetic metasurfaces: physics and applications. Adv. Opt. Photonics, 11, 380(2019). https://doi.org/10.1364/AOP.11.000380

    [99] L. Li et al. Intelligent metasurfaces: control, communication and computing. Elight, 2, 1(2022). https://doi.org/10.1186/s43593-022-00013-3

    [100] F. Guan et al. Overcoming losses in superlenses with synthetic waves of complex frequency. Science, 381, 6659(2023). https://doi.org/10.1126/science.adi1267

    [101] S. Dong et al. Optically transparent meta-window for satellite signal reception. Opt. Laser Technol., 176, 110949(2024). https://doi.org/10.1016/j.optlastec.2024.110949

    [102] K. Xue et al. Transmissive reconfigurable metasurface enabling independent control of active and passive modules through weak coupling. Photon. Res., 7, 1449(2024). https://doi.org/10.1364/PRJ.517652

    [103] M. Kang, J. Chen, Y. D. Chong. Chiral exceptional points in metasurfaces. Phys. Rev. A, 94, 033834(2016). https://doi.org/10.1103/PhysRevA.94.033834

    [104] J. Yang et al. Conceptual radar trap model realized via polarization conversion metasurface. Opt. Express, 30, 1936(2022). https://doi.org/10.1364/OE.438851

    [105] M. Lawrence et al. Manifestation of P T Symmetry breaking in polarization space with Terahertz metasurfaces. Phys. Rev. Lett., 113, 093901(2014). https://doi.org/10.1103/PhysRevLett.113.093901

    [106] S. H. Park et al. Observation of an exceptional point in a non-Hermitian metasurface. Nanophotonics, 9, 1031(2020). https://doi.org/10.1515/nanoph-2019-0489

    [107] D. Wang et al. Superconductive PT-symmetry phase transition in metasurfaces. Appl. Phys. Lett., 110, 021104(2017). https://doi.org/10.1063/1.4973769

    [108] Q. Song et al. Plasmonic topological metasurface by encircling an exceptional point. Science, 373, 1133(2021). https://doi.org/10.1126/science.abj3179

    [109] G. Cao et al. Polarization-insensitive unidirectional meta-retroreflector. Opt. Laser Technol., 156, 108497(2022). https://doi.org/10.1016/j.optlastec.2022.108497

    [110] J. Mai et al. Double exceptional points in grating coupled metal-insulator-metal heterostructure. Opt. Express, 30, 40053(2022). https://doi.org/10.1364/OE.472961

    [111] S. Li et al. Exceptional point in a metal-graphene hybrid metasurface with tunable asymmetric loss. Opt. Express, 28, 20083(2020). https://doi.org/10.1364/OE.391917

    [112] Q. Liu et al. Exceptional points in Fano-resonant graphene metamaterials. Opt. Express, 25, 7203(2017). https://doi.org/10.1364/OE.25.007203

    [113] M. Kang, W. Zhu, I. D. Rukhlenko. Experimental observation of the topological structure of exceptional points in an ultrathin hybridized metamaterial. Phys. Rev. A, 96, 063823(2017). https://doi.org/10.1103/PhysRevA.96.063823

    [114] X. Wang et al. Extreme asymmetry in metasurfaces via evanescent fields engineering: angular-asymmetric absorption. Phys. Rev. Lett., 121, 256802(2018). https://doi.org/10.1103/PhysRevLett.121.256802

    [115] N. S. Nye et al. Flexible PT -symmetric optical metasurfaces. Phys. Rev. Appl., 13, 064005(2020). https://doi.org/10.1103/PhysRevApplied.13.064005

    [116] Z. Li et al. Parity-time symmetry transition and exceptional points in terahertz metal–graphene hybrid metasurface with switchable transmission and reflection characteristics. Phys. Chem. Chem. Phys., 25, 6510(2023). https://doi.org/10.1039/D2CP05699B

    [117] X. Gu et al. Unidirectional reflectionless propagation in a non-ideal parity-time metasurface based on far field coupling. Opt. Express, 25, 11778(2017). https://doi.org/10.1364/OE.25.011778

    [118] Y. Li et al. Bifunctional sensing based on an exceptional point with bilayer metasurfaces. Opt. Express, 31, 492(2023). https://doi.org/10.1364/OE.478546

    [119] C. Zeng et al. Enhanced sensitivity at high-order exceptional points in a passive wireless sensing system. Opt. Express, 27, 27562(2019). https://doi.org/10.1364/OE.27.027562

    [120] B. Jin et al. High-performance Terahertz sensing at exceptional points in a bilayer structure. Adv. Theory Simul., 1, 1800070(2018). https://doi.org/10.1002/adts.201800070

    [121] Y. Zhao, A. Alù. Manipulating light polarization with ultrathin plasmonic metasurfaces. Phys. Rev. B, 84, 205428(2011). https://doi.org/10.1103/PhysRevB.84.205428

    [122] X. Wu et al. Study of a high-index dielectric non-hermitian metasurface and its application in holograms. ACS Omega, 7, 44743(2022). https://doi.org/10.1021/acsomega.2c04448

    [123] C. A. Valagiannopoulos, F. Monticone, A. Alù. PT-symmetric planar devices for field transformation and imaging. J. Opt., 18, 044028(2016). https://doi.org/10.1088/2040-8978/18/4/044028

    [124] R. Fleury, D. L. Sounas, A. Alù. Negative refraction and planar focusing based on parity-time symmetric metasurfaces. Phys. Rev. Lett., 113, 023903(2014). https://doi.org/10.1103/PhysRevLett.113.023903

    [125] C. F. Doiron, G. V. Naik. Non-Hermitian selective thermal emitters using metal–semiconductor hybrid resonators. Adv. Mater., 31, 1904154(2019). https://doi.org/10.1002/adma.201904154

    [126] B. Zhao, L.-S. Sun, J. Chen. Hybrid parity-time modulation phase and geometric phase in metasurfaces. Opt. Express, 28, 28896(2020). https://doi.org/10.1364/OE.404350

    [127] X. Huang et al. Non-Hermitian skin effect and nonreciprocity induced by dissipative couplings. Phys. Rev. A, 109, L021503(2024). https://doi.org/10.1103/PhysRevA.109.L021503

    [128] X. Zhang et al. A review on non-Hermitian skin effect. Adv. Phys. X, 7, 2109431(2022). https://doi.org/10.1080/23746149.2022.2109431

    [129] E. L. Pereira et al. Non-Hermitian topology and criticality in photonic arrays with engineered losses. Phys. Rev. Res., 6, 023004(2024). https://doi.org/10.1103/PhysRevResearch.6.023004

    [130] K. Ding, C. Fang, G. Ma. Non-Hermitian topology and exceptional-point geometries. Nat. Rev. Phys., 4, 745(2022). https://doi.org/10.1038/s42254-022-00516-5

    [131] C. Chen, L. Jin, R.-B. Liu. Sensitivity of parameter estimation near the exceptional point of a non-Hermitian system. New J. Phys., 21, 083002(2019). https://doi.org/10.1088/1367-2630/ab32ab

    [132] H. Loughlin, V. Sudhir. Exceptional-point sensors offer no fundamental signal-to-noise ratio enhancement. Phys. Rev. Lett., 132, 243601(2024). https://doi.org/10.1103/PhysRevLett.132.243601

    [133] W. Langbein. No exceptional precision of exceptional-point sensors. Phys. Rev. A, 98, 023805(2018). https://doi.org/10.1103/PhysRevA.98.023805

    [134] J. Naikoo, R. W. Chhajlany, J. Kołodyński. multiparameter estimation perspective on Non-Hermitian singularity-enhanced sensing. Phys. Rev. Lett., 131, 220801(2023). https://doi.org/10.1103/PhysRevLett.131.220801

    [135] C. Wolff, C. Tserkezis, N. A. Mortensen. On the time evolution at a fluctuating exceptional point. Nanophotonics, 8, 1319(2019). https://doi.org/10.1515/nanoph-2019-0036

    [136] H. Zhao et al. Non-Hermitian topological light steering. Science, 365, 1163(2019). https://doi.org/10.1126/science.aay1064

    [137] H. Hodaei et al. Enhanced sensitivity at higher-order exceptional points. Nature, 548, 187(2017). https://doi.org/10.1038/nature23280

    [138] M. Y. Nada, M. A. K. Othman, F. Capolino. Theory of coupled resonator optical waveguides exhibiting high-order exceptional points of degeneracy. Phys. Rev. B, 96, 184304(2017). https://doi.org/10.1103/PhysRevB.96.184304

    [139] Y. Wu et al. High-order exceptional point based optical sensor. Opt. Express, 29, 6080(2021). https://doi.org/10.1364/OE.418644

    [140] X. Zhou et al. Higher-order singularities in phase-tracked electromechanical oscillators. Nat. Commun., 14, 7944(2023). https://doi.org/10.1038/s41467-023-43708-y

    [141] C. Zeng et al. Ultra-sensitive passive wireless sensor exploiting high-order exceptional point for weakly coupling detection. New J. Phys., 23, 063008(2021). https://doi.org/10.1088/1367-2630/abfc69

    [142] H. Yang et al. Scalable higher-order exceptional surface with passive resonators. Opt. Lett., 46, 4025(2021). https://doi.org/10.1364/OL.435843

    [143] S. Jiang et al. Experimental realization of exceptional surfaces enhanced displacement sensing with robustness. Appl. Phys. Lett., 123, 201106(2023). https://doi.org/10.1063/5.0171249

    [144] M. De Carlo et al. Design of a trap-assisted exceptional-surface- enhanced silicon-on-insulator particle sensor. J. Lightw. Technol., 40, 6021(2022). https://doi.org/10.1109/JLT.2022.3185829

    [145] D. D. Smith et al. Beyond the Petermann limit: can exceptional points increase sensor precision?(2021). http://arxiv.org/abs/2005.12213

    [146] Y. Zhang et al. Reconfigurable exceptional point-based sensing with 0.001λ sensitivity using spoof localized surface plasmons. Adv. Photon. Nexus, 3, 056004(2024). https://doi.org/10.1117/1.APN.3.5.056004

    [147] Z. Liao et al. Microwave plasmonic exceptional points for enhanced sensing. Laser Photonics Rev., 17, 2300276(2023). https://doi.org/10.1002/lpor.202300276

    [148] T. S. Bai et al. Exceptional point in a microwave plasmonic dipole resonator for sub-microliter solution sensing. Adv. Funct. Mater., 34, 2312170(2024). https://doi.org/10.1002/adfm.202312170

    [149] A. K. Chatterjee, S. Takada, H. Hayakawa. Multiple quantum Mpemba effect: exceptional points and oscillations. Phys. Rev. A, 110, 022213(2024). https://doi.org/10.1103/PhysRevA.110.022213

    [150] J. Zhang et al. Observation of quantum strong Mpemba effect. Nat. Commun., 16, 301(2025). https://doi.org/10.1038/s41467-024-54303-0

    [151] W.-C. Wang et al. Observation of PT-symmetric quantum coherence in a single ion system. Phys. Rev. A, 103, L020201(2021). https://doi.org/10.1103/PhysRevA.103.L020201

    Shaohua Dong, Heng Wei, Zhipeng Li, Guangtao Cao, Kun Xue, Yang Chen, Cheng-Wei Qiu, "Exceptional-point optics with loss engineering," Photon. Insights 4, R02 (2025)
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