Epsilon‐Near‐Zero Photonics: A New Platform for Integrated Devices

Abstract

Epsilon‐near‐zero (ENZ) photonics is the study of light–matter interactions in the presence of structures with near‐zero permittivity and has been emerging as an important field of research in recent years. The introduction of zero permittivity structures also introduces a number of unique features to traditional photonic systems, including decoupling of their spatial and temporal field variations, tunneling through arbitrary channels, constant phase transmission, strong field confinement, and ultrafast phase transitions. Along with the continued developments in the theoretical research on ENZ photonics, many novel functional photonic devices are proposed and demonstrated experimentally, thus indicating the broad prospects of ENZ photonics for fabrication of high‐performance integrated photonic chips. Zero‐epsilon materials, which represent a singular point in optical materials, are expected to lead to remarkable developments in the fields of integrated photonic devices and optical interconnections. This review summarizes the underlying principles, the related novel physical effects, the fundamental principles for realization of ENZ photonic systems, and the integrated device applications of ENZ photonics. The review concludes with a brief overview of the challenges to be confronted and the potential development directions that may be pursued to realize extensive applications of ENZ photonics in the field of integrated photonic signal processing.

On Dyakonov–Voigt surface waves guided by the planar interface of dissipative materials

“…9 for δ = 0.5 and ψ = 5 • , so that ε B = 0.016 + 0.001i. Parethetically, such values of relative permittivity that are close to zero can be realized using metamaterial technologies [34,35]. The plots in Fig.…”

Self-interaction of ultrashort pulses in an epsilon-near-zero nonlinear material at the telecom wavelength

“…In the recent decade, the epsilon-near-zero (ENZ) materials have drawn much interest in studies of plasmonic metamaterials [1] and photonics [2,3]. By tuning its permittivity to a near-zero value, the ENZ material can feature a refractive index much lower than 1 and other extraordinary optical properties, such as electromagnetic energy tunneling [4], directive emission with invariable phase [5], amplification of electric field [6], enhancement of nonlinearity [7], pulse shaping and tailoring [8,9], slow-light trapping [10], and the creation of confined ENZ modes [11,12].…”

“…State-of-the-art material technologies for transparent conducting oxides (TCOs) [13][14][15][16] are widely used as ENZ materials, due to their wide ENZ spectral region, extending from ultraviolet to mid-infrared [1,3]. The ENZ point, at which the real part of the permittivity falls to zero, can be tuned by modulating the dopant concentration.…”

“…Based on TCO ENZ materials, ultrahigh nonlinear Kerr response [17,18], all-optical switching [19,20], second-harmonic generation (SHG) [21], third-harmonic generation (THG) [22], and high-harmonic generation [23] were all demonstrated. Among various sorts of TCOs, indium tin oxide (ITO), a common material used in displays, is often employed in studies of ENZ, due to its low cost, high nonlinearity [17], and near-infrared ENZ region [3].…”

Linear-crossing metamaterials mimicked by multi-layers with two kinds of single negative materials

“…However, the dispersion of natural materials is limited and difficult to control flexibly. Metamaterials, artificial media with subwavelength meta-atoms, can possess a variety of unusual photonic dispersions and effectively tailor the light-matter interaction in unprecedented ways [6][7][8][9]. Among them, hyperbolic metamaterials (HMMs) with open hyperbolic IFCs have received widespread attention because of their characteristics of supporting high-k modes [10,11].…”