PT-symmetry in photonics, metamaterials and plasmonic systems III

10:20 Invited talk : Exceptional point dynamics of a bianisotropic transmission line

Shiyi Xiao (1),Yong Sun (2),Hong Chen (2),Jensen Li (1)

(1)University of Birmingham (United Kingdom) , (2)Tongji University (China)

Bianisotropic metamaterials, with different impedances in the forward and backward propagation directions, can be used to achieve a unidirectional character in the reflection. Here, we show that such phenomenon can be associated to the exceptional point of an effective Hamiltonian, which can be regarded as the constitutive matrix of the system with non-ideal effective PT symmetry. It is further confirmed by using experiments on a transmission line platform.
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10:40 : Parity-Time Chain of Whispering-Gallery Mode Resonators

Sendy Phang, Ana Vukovic, Stephen Creagh, Trevor Benson, G. Gradoni, Phillip Sewell

University of Nottingham (United Kingdom)

The paper analyses the dispersion characteristics of an infinitely long PT chain made of whispering gallery resonators with gain/loss modulation. The results show that the appearance of the threshold breaking point depends not only on both of coupling and gain/loss modulation but also on the Bloch phase. The Bloch phase is seen as an additional parameter that can reduce or even completely eliminate PT-breaking threshold.
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10:55 Invited talk : Spontaneous Parity-Time Symmetry Breaking and Light Amplification in Moving Media

Mario Silveirinha

University of Coimbra (Portugal)

It is shown that the emergence of optical instabilities in moving systems is strictly related to a spontaneous parity-time symmetry breaking of the relevant time evolution operator. It is proven that the frequency spectrum of lossless systems with moving components is generally complex valued, and has a mirror symmetry with respect to the real-frequency axis. The optical amplification of a light pulse in the broken parity-time symmetry regime is studied.
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