Multi-Channel Optical Isolator Based on Nonlinear Triangular Parity Time Symmetric Lattice

Abstract

We report the design procedure for a broadband multichannel cavity-less optical isolator composed of a triangular perturbed nonlinear Parity Time (PT) symmetric lattice. The interplay between the nonlinearity and PT-symmetric lattice that results in nonreciprocal transmission enables us to design the isolator outputs and inputs positions as desired. In the transmitting regime, a number of solitons that are simultaneously launched into individual inputs positioned appropriately, on the waveguides' gain sides in the periodic lattice, swing along the waveguide until they are self-trapped along the respective waveguides axes, where the isolator outputs are located. In the isolating regime, however, the solitons that are launched into the inputsi.e., the outputs of the transmitting regime-propagate along the waveguides axes, until they exit from the new outputs. Simulations show that the neighboring soliton trajectories in each regime are completely isolated and so are the forward and reverse trajectories in each waveguide cell. Moreover, operation of this cavity-less PT-symmetric isolator that is designed on an inhomogeneous slab waveguide does not suffer from the narrow frequency band limitation, unlike their cavity-based counterparts.

Quantum optical analysis of squeezed state of light through dispersive non-Hermitian optical bilayers

“…The scattering of purely classical light from PTsymmetric structures has led to several engaging optical effects such as optical switching [8], nonreciprocal propagation [9,10], coherent perfect absorbers [11], optical isolation [12,13], extraordinary transmission, reflection, and absorption [14][15][16][17], topological phase transitions [18], optoelectronic oscillators [19], flat bands generated by symmetries [20], and specifically unidirectional invisibility [21][22][23]. These unusual functionalities, which are a direct consequence of the PTsymmetry, are essentially classical.…”

The second-order coherence analysis of number state propagation through dispersive non-Hermitian multilayered structures

“…Under particular conditions—i.e., parity-time (PT) symmetric conditions—a non-Hermitian Hamiltonian can retain an entirely real spectrum of eigenvalues that is usually believed exclusively to belong to Hermitian systems 1 – 3 . PT symmetry can influence systems' functions like nonlinearity 4 – 6 , lasing 6 , 7 , switching 8 , unidirectional invisibility 9 , and non-trivial topologies 10 , 11 . Such systems employ a photonic platform and set the stage for the development of other research fields, such as atomic 12 – 14 and plasmonic systems 15 , and electronic circuits 16 , 17 .…”

Tunable optical isolator using Graphene-photonic crystal-based hybrid system

“…The main obstacle for the application of the developed optical integrated circuits with magneto-optical isolators in a practical system is their low output intensities, due to high losses. Moreover, to implement asymmetrical light propagation, in recent years, nonlinear 2D-photonic crystals [5][6][7][8][9][10][11], nonlinear parity-time symmetric (PTS) structures [12][13][14][15][16][17][18], tunable plasmonic waveguides [19][20][21], optomechanical and optoacoustic configurations [22][23][24][25], structures involving indirect interband transitions [26], asymmetric linear passive structure [27], nonlinear passive graded-index [28], asymmetrically light-absorbing structures using nonlinear materials [29] have been used. Most of the nonlinear PhC based isolators, the Fano resonances created via the interplay between the non-linear effect and the asymmetry round-trip in the structure play a critical role in the isolator efficiency, and its isolation rate [5,6].…”

“…Most of the nonlinear PhC based isolators, the Fano resonances created via the interplay between the non-linear effect and the asymmetry round-trip in the structure play a critical role in the isolator efficiency, and its isolation rate [5,6]. In the optical isolators by PT-symmetry-based configurations, the interactions between the Kerr-nonlinearity effect and the PTS structures lead to the nonreciprocal transmission [12,13]. The optical excitation of a gigahertz guided acoustic mode in a micrometer-sized PhC fiber core results in the experimental demonstration of a reconfigurable all-optical isolator [23].…”