Pseudo-Parity-Time Symmetry in Optical Systems

Abstract

We introduce a novel concept of the pseudo-parity-time (pseudo-PT) symmetry in periodically modulated optical systems with balanced gain and loss. We demonstrate that whether or not the original system is PT symmetric, we can manipulate the property of the PT symmetry by applying a periodic modulation in such a way that the effective system derived by the high-frequency Floquet method is PT symmetric. If the original system is non-PT symmetric, the PT symmetry in the effective system will lead to quasistationary propagation that can be associated with the pseudo-PT symmetry. Our results provide a promising approach for manipulating the PT symmetry of realistic systems.

Nonlinear switching and solitons in PT‐symmetric photonic systems

“…When system parameters are modulated such that underlying system is not PT-symmetric at any modulation cross-section, the overall dynamics can still demonstrate the features of pseudo-PT symmetry [190,191]. The concept of pseudo-PT symmetry corresponds to the PT-symmetry in the effective system, which manifests as quasi-stationary propagation.…”

“…Following Ref. [190], consider a coupler described by Eq. 64 with balanced For φ = 0, π, the corresponding Hamiltonian is not PTsymmetric.…”

Anderson localization in the non-Hermitian Aubry-André-Harper model with physical gain and loss

“…With appropriate conditions, these PT -symmetric Hamiltonians can have purely real energy spectra [7,8]. The properties of PT -symmetric Hamiltonians and the corresponding breaking of this symmetry in many different non-Hermitian systems have been extensively studied [9][10][11][12][13][14][15][16][17][18][19]. Experimentally, there are also many different kinds of realizations of open systems in optical [20][21][22][23], mechanical [24], and electrical [25] setups, which endow the non-Hermitian Hamiltonians more practical signifi-cance.…”

Interplay between Fano resonance andPTsymmetry in non-Hermitian discrete systems

“…One distinguishing feature of PT -symmetric Hamiltonians is the existence of spontaneous symmetry breaking, corresponding to a transition from real to complex spectra [2]. Since then, numerious PT -symmetric systems have been explored in several fields, from the complex extension of quantum mechanics [3,4], to the quantum field theories and mathematical physics [5], open quantum systems [6], the Anderson models for disorder systems [7][8][9], the optical systems with complex refractive indices [10][11][12][13][14][15], and the topological insulators [16,17].…”