The advance of nanophotonics has provided a variety of avenues for light–matter interaction at the nanometer scale through the enriched mechanisms for physical and chemical reactions induced by nanometer-confined optical probes in nanocomposite materials. These emerging nanophotonic devices and materials have enabled researchers to develop disruptive methods of tremendously increasing the storage capacity of current optical memory. In this paper, we present a review of the recent advancements in nanophotonics-enabled optical storage techniques. Particularly, we offer our perspective of using them as optical storage arrays for next-generation exabyte data centers. The science and technology of nanophotonics can help dramatically increase the capacity of optical discs. After reviewing research into next-generation optical data storage, Min Gu, Xiangping Li and Yaoyu Cao from the Swinburne University of Technology in Australia have offered their perspective of the creation of exabyte-scale optical data centers. They report that developments in ’super-resolution recording‚, which allow a light-sensitive material to be exposed to a focal spot that is smaller than the diffraction limit of light, will allow the size of recorded bits to shrink to just a few nanometres in size. This would ultimately allow a single disk to store petabytes of data and thus constitute a key component in optical storage arrays for ultrahigh-capacity optical data centers.

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Optical storage arrays: a perspective for future big data storage

Broadband and polarization-insensitive terahertz absorber based on multilayer metamaterials

Plasmonics and metamaterials have attracted considerable attention over the past decade, owing to the revolutionary impacts that they bring to both the fundamental physics and practical applications in multiple disciplines Although the two fields initially advanced along their individual trajectories in parallel, they started to interfere with each other when metamaterials reached the optical regime The dynamic interplay between plasmonics and metamaterials has generated a number of innovative concepts and approaches, which are impossible with either area alone This review presents the fundamentals, recent advances and future perspectives in the emerging field of plasmonic metamaterials, aiming to open up new exciting opportunities for nanoscience and nanotechnology

Plasmonic Metamaterials

Acoustic metamaterial science is an emerging field at the frontier of modern acoustics. It provides a prominent platform for acoustic wave control in subwavelength-sized metadevices or metasystems. However, most of the metamaterials can only work in a narrow frequency band once fabricated, which limits the practical application of acoustic metamaterials. This paper highlights some recent progress in tunable acoustic metamaterials based on various modulation techniques. Acoustic metamaterials have been designed to control the attenuation of acoustic waves, invisibility cloaking, and acoustic wavefront engineering, such as focusing via manipulating the acoustic impedance of metamaterials. The reviewed techniques are promising in extending the novel acoustics response into wider frequency bands, in that tunable acoustic metamaterials may be exploited for unusual applications compared to conventional acoustic devices.

A Review of Tunable Acoustic Metamaterials

Polypyrrole (PPy) composites incorporating yttrium iron garnet (YIG) particles were prepared by an in situ oxidative polymerization method. The effects of YIG particle loading level on the radio-frequency (RF) electromagnetic properties of the YIG/PPy composites were systematically investigated. A negative permittivity behaviour combined with metal-like conduction was observed in the PPy composites, which was due to the low-frequency plasmonic state of free electrons in the formed conducting PPy networks. The Drude model was used to give a good description of the dielectric response. After increasing the YIG loading, the plasma frequency, at which the real part of permittivity changed from negative to positive, shifted to a lower frequency, and the magnitude (absolute value) of negative permittivity also became smaller. In addition, the permeability of the composites showed a relaxation-type frequency dispersion, which was attributed to the combined effect of the magnetic resonance of YIG particles and diamagnetic response of PPy conducting networks. This work can pave the way for exploiting the regulation mechanism of negative permittivity, benefiting the practical applications of polymer metamaterials.

Tunable negative permittivity and magnetic performance of yttrium iron garnet/polypyrrole metacomposites at the RF frequency

Experimental investigation of the reverse-Doppler shift of electromagnetic waves has previously been restricted to the microwave regime. Here, direct confirmation of the Doppler effect is reported at the infrared wavelength of 10.6 µm using a moving photonic crystal exhibiting a negative refractive index.

https://www.cjoint.com/data1/1dopJPFAWgB_photon2.pdf

Wei Qian

Papers

Observation of the inverse Doppler effect in negative-index materials at optical frequencies