Parity-time-symmetric optical coupler with birefringent arms

Abstract

In this work, we propose a parity-time (PT -) symmetric optical coupler whose arms are birefringent waveguides as a realistic physical model which leads to a so-called quadrimer i.e., a four complex field setting. We seek stationary solutions of the resulting linear and nonlinear model, identifying its linear point of PT symmetry breaking and examining the corresponding nonlinear solutions that persist up to this point, as well as, so-called, ghost states that bifurcate from them. We obtain the relevant symmetry breaking bifurcations between symmetric (circularly polarized) and asymmetric (elliptically polarized) states and numerically follow the associated dynamics which give rise to growth/decay even within the PT -symmetric phase. Our symmetric stationary nonlinear solutions are found to terminate in saddle-center bifurcations which are analogous to the linear PT -phase transition. We found that the PT symmetry significantly changes the stability and dynamical properties of the modes with different polarizations.

Nonlinear switching and solitons in PT‐symmetric photonic systems

“…The plaquette models can describe real physical systems such as PT-symmetric multi-modes fibers [72][73][74], Figure 11 (a) PT-symmetric birefringent arm coupler with principal optical axes of the two waveguides are π/4 rotated with respect to each other, and (b) its graph representation in form of PT-symmetric plaquette. Red ("+") and blue ("-") colors denote active and lossy waveguides, respectively.…”

“…Red ("+") and blue ("-") colors denote active and lossy waveguides, respectively. Adopted from [72].…”

“…including PT-symmetric coupler with birefringent arms was considered in [72]. The schematic of such a coupler and its graph representation are shown in Fig.…”

Parity–time-symmetric closed form optical quadrimer waveguides

“…In this work, we study a closed form PT-symmetric quadrimer optical waveguide structure. It is appropriate to mention that several authors have studied closed form quadrimer structures in various contexts [27][28][29][30]. The beam dynamics of the structure is studied numerically.…”

PT-symmetric coupler withχ(2)nonlinearity

“…Finally, a nonlinear dimer or more generally the so-called nonlinear "oligomers" (i.e., few site configurations) introduced in [21] (see also [22]), were shown to allow for the existence of continuous families of nonlinear modes [23]. Among these, a PT -symmetric quadrimer model naturally appears in the description of light propagation in a birefringent coupler [24]. Discrete solitons in different types of infinite PT -symmetric waveguide arrays were studied numerically [25] and analytical proofs for their existence have been proposed using the anticontnuum limit [26] and via analysis of the modes bifurcating from the linear limit [27].…”