Roadmap on optical metamaterials

Abstract

Optical metamaterials have redefined how we understand light in notable ways: from strong response to optical magnetic fields, negative refraction, fast and slow light propagation in zero index and trapping structures, to flat, thin and perfect lenses. Many rules of thumb regarding optics, such as mu = 1, now have an exception, and basic formulas, such as the Fresnel equations, have been expanded. The field of metamaterials has developed strongly over the past two decades. Leveraging structured materials systems to generate tailored response to a stimulus, it has grown to encompass research in optics, electromagnetics, acoustics and, increasingly, novel hybrid materials responses. This roadmap is an effort to present emerging fronts in areas of optical metamaterials that could contribute and apply to other research communities. By anchoring each contribution in current work and prospectively discussing future potential and directions, the authors are translating the work of the field in selected areas to a wider community and offering an incentive for outside researchers to engage our community where solid links do not already exist.

Template‐Directed Solidification of Eutectic Optical Materials

“…[4][5][6] Light in the visible spectrum can be manipulated, although the tolerance for defects is exceedingly low at visible frequencies, and the number of materials with the appropriate properties is limited. [9] However, it is challenging to fabricate large-area bulk materials with these techniques, especially with intricate internal structures. [9] However, it is challenging to fabricate large-area bulk materials with these techniques, especially with intricate internal structures.…”

“…[8] Additionally, many materials with promising optical properties are not compatible with these top-down patterning methods. [9][10][11][12][13] Colloidal self-assembly, however, only offers a limited set of symmetries (generally those of close packed arrangements), and a spherical basis. [9][10][11][12][13] Colloidal self-assembly, however, only offers a limited set of symmetries (generally those of close packed arrangements), and a spherical basis.…”

Ultra-fast transient plasmonics using transparent conductive oxides

“…The sample consisted in a≅1 μm layer of AZO deposited on a thick 0.5 mm fused silica glass. The transparent conductive film was deposited by using pulsed laser deposition in an oxygen deprived atmosphere with the purpose to further increase the intrinsic carrier concentration and set the ENZ wavelength in the NIR around 1.3 μm [38]. Figure 2 shows, in the colour bar, both the transient reflected (a) and transmitted (b) power spectral densities as a function of the time delay τ between the pump and a probe signals, with the latter set at λ=1290 nm (few nanometres apart from the ENZ wavelength).…”

Editorial: Guided-Wave Optics

“…Other well-known examples of purposely designed artificial optical media with extraordinary properties include hyperbolic metamaterials, whose tensors of the dielectric permittivity and/or magnetic permeability feature principal values of opposite signs [83,84], planar metasurfaces [85,86], epsilon-near-zero materials, in which the refractive index nearly vanishes [87], photonic topological insulators [88,89] (which exemplify the area of topological photonics [90]), and others. The use of such media opens numerous possibilities to implement diverse optical effects, including nonlinear ones [91] and guided-wave propagation, in forms that were not known previously (for instance, in the form of the surface waveguiding in photonic topological insulators, which is immune to scattering on defects because the scattering is suppressed by the topology of the guiding system), and are unified under the name of metaoptics [92,93]. Another unifying concept is nanophotonics, the name originating from the fact that many of these materials are assembled of elements with sizes measured on the nanometer scale (which is deeply subwavelength, in terms of optics).…”