Exceptional points and spectral singularities in active epsilon-near-zero plasmonic waveguides

Abstract

We present a nanoscale active plasmonic waveguide system consisting of an array of periodic slits that can exhibit exceptional points and spectral singularities leading to several novel functionalities. The proposed symmetric active system operates near its cut-off wavelength and behaves as an effective epsilon-near-zero (ENZ) medium. We demonstrate the formation of an exceptional point (EP) that is accessed with very low gain coefficient values, a unique feature of the proposed nanoscale symmetric plasmonic configuration. Reflectionless ENZ transmission and perfect loss-compensation are realized at the EP which coincides with the effective ENZ resonance wavelength of the proposed array of active plasmonic waveguides. When we further increase the gain coefficient of the dielectric material loaded in the slits, a spectral singularity occurs at the ENZ resonance leading to super scattering (lasing) response at both forward and backward directions. These interesting effects are achieved by materials characterized by very small gain coefficients with practical values and at subwavelength scales due to the strong and homogeneous field enhancement inside the active slits at the ENZ resonance leading to enhanced light-matter interaction. We theoretically analyze the obtained EP, as well as the divergent spectral singularity, using a transmission-line model and investigate the addition of a second incident wave and nonlinearities in the response of the proposed active ENZ plasmonic system. Our findings provide a novel route towards interesting nanophotonic applications, such as reflectionless active ENZ media, unidirectional coherent perfect absorbers, nanolasers, and strong optical bistability and all-optical switching nanodevices.

References in corpus (27)

• Unidirectional Invisibility induced by PT-Symmetric Periodic Structures
• The physics of exceptional points
• Topological Band Theory for Non-Hermitian Hamiltonians
• Nonlinear waves in $\mathcal{P}\mathcal{T}$-symmetric systems
• Coherent Perfect Absorbers: Time-reversed Lasers
• Dynamically encircling exceptional points in a waveguide: asymmetric mode switching from the breakdown of adiabaticity
• Loss-induced suppression and revival of lasing
• Topological energy transfer in an optomechanical system with exceptional points
• PT-symmetry breaking and laser-absorber modes in optical scattering systems
• PT-symmetric laser-absorber
• Spawning rings of exceptional points out of Dirac cones
• Unidirectional Nonlinear PT-symmetric Optical Structures
• Spectral Singularities of Complex Scattering Potentials and Infinite Reflection and Transmission Coefficients at real Energies
• Observation of Asymmetric Transport in Structures with Active Nonlinearities
• General description of quasi-adiabatic dynamical phenomena near exceptional points
• Optical Nanotransmission Lines: Synthesis of Planar Left-Handed Metamaterials in the Infrared and Visible Regimes
• Light stops at exceptional points
• Transmission-Line Analysis of Epsilon-Near-Zero (ENZ)-Filled Narrow Channels
• Enhanced Super-Radiance in Epsilon-Near-Zero Plasmonic Channels
• Optical Tunneling through Arbitrarily-Shaped Plasmonic Channels and Sharp Bends
• Tunneling of Obliquely-Incident Waves through PT-Symmetric Epsilon-Near-Zero Bi-Layers
• $\mathcal{P}\mathcal{T}$-Symmetry-Induced Wave Confinement and Guiding in Epsilon-Near-Zero Metamaterials
• Simultaneous Realization of Coherent Perfect Absorber and Laser by Zero-Index Media with both Gain and Loss
• Regularization of the spectral singularity in $\mathcal{P}\mathcal{T}$-symmetric systems by all order nonlinearities: Nonreciprocity and optical isolation
• Tunable nonlinear coherent perfect absorption with epsilon-near-zero plasmonic waveguides
• Exceptional Points in three-dimensional Nanostructures
• Controlling collective spontaneous emission with plasmonic waveguides

Cited by in corpus (15)

• Resonance Energy Transfer and Quantum Entanglement Mediated by Epsilon-Near-Zero and Other Plasmonic Waveguide Systems
• Nonreciprocal Transmission in Nonlinear PT-Symmetric Metamaterials Using Epsilon-near-Zero Media Doped with Defects
• Berreman Embedded Eigenstates for Narrowband Absorption and Thermal Emission
• Nonreciprocal transmission of electromagnetic waves with nonlinear active plasmonic metasurfaces
• Multiqubit entanglement and quantum phase gates with epsilon-near-zero plasmonic waveguides
• High-order spectral singularity
• Harnessing Spectral Singularities in Non-Hermitian Cylindrical Structures
• Spectral singularities and tunable slab lasers with 2D material coating
• Omnidirectional field enhancements drive giant nonlinearities in epsilon-near-zero waveguides
• Exceptional points in parity-time symmetric plasmonic Huygens metasurfaces
• Plasmonic Waveguides to Enhance Quantum Electrodynamic Phenomena at the Nanoscale
• Solving scattering problems in the half-line using methods developed for scattering in the full line
• Attaining near-ideal Dicke superradiance in expanded spatial domains
• Deterministic steady-state subradiance within a single-excitation basis
• Plasmonic random laser on an optical fiber tip