We investigated the Talbot effect in an anti-parity-time(PT)symmetric synthetic photonic lattice composed of two coupled fiber loops.We calculated the band structures and found that with an increase in the gain-loss p...We investigated the Talbot effect in an anti-parity-time(PT)symmetric synthetic photonic lattice composed of two coupled fiber loops.We calculated the band structures and found that with an increase in the gain-loss parameter,the band transitions from a real spectrum to a complex spectrum.We study the influence of phase in the Hermitian operator on the Talbot effect,and the Talbot effect disappears when the period of the input field is N>8.Further study shows that the variation of Talbot distance can also be modulated by non-Hermitian coefficients of gain and loss.This work may find significant applications in pulse repetition-rate multiplication,temporal invisibility,and tunable intensity amplifiers.展开更多
Nonreciprocal elements,such as isolators and circulators,play an important role in classical and quantum information processing.Recently,strong nonreciprocal effects have been experimentally demonstrated in cavity opt...Nonreciprocal elements,such as isolators and circulators,play an important role in classical and quantum information processing.Recently,strong nonreciprocal effects have been experimentally demonstrated in cavity optomechanical systems.In these approaches,the bandwidth of the nonreciprocal photon transmission is limited by the mechanical resonator linewidth,which is arguably much smaller than the linewidths of the cavity modes in most electromechanical or optomechanical devices.In this work,we demonstrate broadband nonreciprocal photon transmission in the reversed-dissipation regime,where the mechanical mode with a large decay rate can be adiabatically eliminated while mediating anti-PT-symmetric dissipative coupling with two kinds of phase factors.Adjusting the relative phases allows the observation of periodic Riemann-sheet structures with distributed exceptional points(Eps).At the Eps,destructive quantum interference breaks both theT-andP-inversion symmetry,resulting in unidirectional and chiral photon transmissions.In the reversed-dissipation regime,the nonreciprocal bandwidth is no longer limited by the mechanical mode linewidth but is improved to the linewidth of the cavity resonance.Furthermore,we find that the direction of the unidirectional and chiral energy transfer could be reversed by changing the parity of the Eps.Extending non-Hermitian couplings to a three-cavity model,the broken anti-PT-symmetry allows us to observe high-order Eps,at which a parity-dependent chiral circulator is demonstrated.The driving-phase controlled periodical Riemann sheets allow observation of the parity-dependent unidirectional and chiral energy transfer and thus provide a useful cell for building up nonreciprocal array and realizing topological,e.g.,isolators,circulators,or amplifiers.展开更多
Two types of one-dimensional(1D)anti-PT-symmetric periodic ring optical waveguide networks,consisting of gain and loss materials,are constructed.The singular optical propagation properties of these networks are invest...Two types of one-dimensional(1D)anti-PT-symmetric periodic ring optical waveguide networks,consisting of gain and loss materials,are constructed.The singular optical propagation properties of these networks are investigated.The results show that the system composed of gain materials exhibits characteristics of ultra-strong transmission and bidirectional reflection.Conversely,the system composed of loss materials demonstrates equal transmittance and reflectance at some frequencies.In both the systems,a new type of total reflection phenomenon is observed.When the imaginary part of the refractive indices of waveguide segments is smaller than 10-5,the system shows bidirectional transparency with the transmittance tending to be 1 and reflectivity to be smaller than 10-8 at some bands.When the refractive indices of the waveguide segments are real,the system will be bidirectional transparent at the full band.These findings may deepen the understanding of anti-PT-symmetric optical systems and optical waveguide networks,and possess potential applications in efficient optical energy storage,ultra-sensitive optical filters,ultra-sensitive all-optical switches,integrated optical chips,stealth physics,and so on.展开更多
基金supported by the National Key Research and Development Program of China(Nos.2022YFA1404800 and 2019YFA0705000)the National Natural Science Foundation of China(Nos.12104272,12274270,91950104,12192254,92250304,and 11974218)the Local Science and Technology Development Project of the Central Government(No.YDZX20203700001766)。
文摘We investigated the Talbot effect in an anti-parity-time(PT)symmetric synthetic photonic lattice composed of two coupled fiber loops.We calculated the band structures and found that with an increase in the gain-loss parameter,the band transitions from a real spectrum to a complex spectrum.We study the influence of phase in the Hermitian operator on the Talbot effect,and the Talbot effect disappears when the period of the input field is N>8.Further study shows that the variation of Talbot distance can also be modulated by non-Hermitian coefficients of gain and loss.This work may find significant applications in pulse repetition-rate multiplication,temporal invisibility,and tunable intensity amplifiers.
基金supported by the China Postdoctoral Science Foundation under Grant No.2021M700442Y.L.Liu acknowledges the support of the Natural Science Foundation of China(NSFC)under Grant No.12004044+5 种基金H.F.Y acknowledges the support from the NSFC of China(11890704)the NSF of Beijing(Z190012)T.F.Li acknowledges the support of the Development Program of China(2016YFA0301200)the National Natural Science Foundation of China(62074091,and U1930402)the Science Challenge Project(TZ2018003)Tsinghua University Initiative Scientific Research Program.
文摘Nonreciprocal elements,such as isolators and circulators,play an important role in classical and quantum information processing.Recently,strong nonreciprocal effects have been experimentally demonstrated in cavity optomechanical systems.In these approaches,the bandwidth of the nonreciprocal photon transmission is limited by the mechanical resonator linewidth,which is arguably much smaller than the linewidths of the cavity modes in most electromechanical or optomechanical devices.In this work,we demonstrate broadband nonreciprocal photon transmission in the reversed-dissipation regime,where the mechanical mode with a large decay rate can be adiabatically eliminated while mediating anti-PT-symmetric dissipative coupling with two kinds of phase factors.Adjusting the relative phases allows the observation of periodic Riemann-sheet structures with distributed exceptional points(Eps).At the Eps,destructive quantum interference breaks both theT-andP-inversion symmetry,resulting in unidirectional and chiral photon transmissions.In the reversed-dissipation regime,the nonreciprocal bandwidth is no longer limited by the mechanical mode linewidth but is improved to the linewidth of the cavity resonance.Furthermore,we find that the direction of the unidirectional and chiral energy transfer could be reversed by changing the parity of the Eps.Extending non-Hermitian couplings to a three-cavity model,the broken anti-PT-symmetry allows us to observe high-order Eps,at which a parity-dependent chiral circulator is demonstrated.The driving-phase controlled periodical Riemann sheets allow observation of the parity-dependent unidirectional and chiral energy transfer and thus provide a useful cell for building up nonreciprocal array and realizing topological,e.g.,isolators,circulators,or amplifiers.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11674107,61475049,11775083,61774062,and 61771205).
文摘Two types of one-dimensional(1D)anti-PT-symmetric periodic ring optical waveguide networks,consisting of gain and loss materials,are constructed.The singular optical propagation properties of these networks are investigated.The results show that the system composed of gain materials exhibits characteristics of ultra-strong transmission and bidirectional reflection.Conversely,the system composed of loss materials demonstrates equal transmittance and reflectance at some frequencies.In both the systems,a new type of total reflection phenomenon is observed.When the imaginary part of the refractive indices of waveguide segments is smaller than 10-5,the system shows bidirectional transparency with the transmittance tending to be 1 and reflectivity to be smaller than 10-8 at some bands.When the refractive indices of the waveguide segments are real,the system will be bidirectional transparent at the full band.These findings may deepen the understanding of anti-PT-symmetric optical systems and optical waveguide networks,and possess potential applications in efficient optical energy storage,ultra-sensitive optical filters,ultra-sensitive all-optical switches,integrated optical chips,stealth physics,and so on.
