Explore the vast range of titles available.

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. Data storage: Nanophotonics promise 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.

In the past decade, research in the field of artificial photosynthesis has shifted from simple, inorganic semiconductors to more abundant, polymeric materials. For example, polymeric carbon nitrides have emerged as promising materials for metal-free semiconductors and metal-free photocatalysts. Polymeric carbon nitride (melon) and related carbon nitride materials are desirable alternatives to industrially used catalysts because they are easily synthesized from abundant and inexpensive starting materials. Furthermore, these materials are chemically benign because they do not contain heavy metal ions, thereby facilitating handling and disposal. In this Review, we discuss the building blocks of carbon nitride materials and examine how strategies in synthesis, templating and post-processing translate from the molecular level to macroscopic properties, such as optical and electronic bandgap. Applications of carbon nitride materials in bulk heterojunctions, laser-patterned memory devices and energy storage devices indicate that photocatalytic overall water splitting on an industrial scale may be realized in the near future and reveal a new avenue of ‘post-silicon electronics’. Carbon nitrides are potentially cheap and metal-free alternatives for catalysts, semiconductors, battery materials and memory devices. In this Review, we discuss the synthesis, design and morphology of these materials, and reflect on the ability of methods such as templating, etching, dye sensitization, heteroatom doping and co-polymerization, as well as the assembly of various heterojunctions, to improve device performance.

The exponential growth of information stored in data centers and computational power required for various data-intensive applications, such as deep learning and AI, call for new strategies to improve or move beyond the traditional von Neumann architecture. Recent achievements in information storage and computation in the optical domain, enabling energy-efficient, fast, and high-bandwidth data processing, show great potential for photonics to overcome the von Neumann bottleneck and reduce the energy wasted to Joule heating. Optically readable memories are fundamental in this process, and while light-based storage has traditionally (and commercially) employed free-space optics, recent developments in photonic integrated circuits (PICs) and optical nano-materials have opened the doors to new opportunities on-chip. Photonic memories have yet to rival their electronic digital counterparts in storage density; however, their inherent analog nature and ultrahigh bandwidth make them ideal for unconventional computing strategies. Here, we review emerging nanophotonic devices that possess memory capabilities by elaborating on their tunable mechanisms and evaluating them in terms of scalability and device performance. Moreover, we discuss the progress on large-scale architectures for photonic memory arrays and optical computing primarily based on memory performance.

Photochromic materials have drawn growing attention because using light as a stimulus has been regarded as a convenient and environmental-friendly way to control properties of smart materials. While photoresponsive systems that are capable of showing multiple-state photochromism are attractive, the development of materials with such capabilities has remained a challenging task. Here we show that a benzo[ b ]phosphole thieno[3,2 ‑b ]phosphole-containing alkynylgold(I) complex features multiple photoinduced color changes, in which the gold(I) metal center plays an important role in separating two photoactive units that leads to the suppression of intramolecular quenching processes of the excited states. More importantly, the exclusive photochemical reactivity of the thieno[3,2 ‑b ]phosphole moiety of the gold(I) complex can be initiated upon photoirradiation of visible light. Stepwise photochromism of the gold(I) complex has been made possible, offering an effective strategy for the construction of multiple-state photochromic materials with multiple photocontrolled states to enhance the storage capacity of potential optical memory devices. Photoresponsive compounds have potential applications in various fields, including the development of smart materials and switches. Here the authors report a gold(I) complex that undergoes multiple photoinduced color changes upon excitation of light at specific wavelengths, offering an enhanced storage capacity towards optical memory devices.

Chalcogenides—alloys based on group-16 ‘chalcogen’ elements (sulfur, selenium, and tellurium) covalently bound to ‘network formers’ such as arsenic, germanium, antimony, and gallium—have a variety of technologically useful properties, including infrared transparency, high optical nonlinearity, photorefractivity and readily induced, reversible, non-volatile structural phase switching. Such phase-change materials are of enormous interest in the fields of plasmonics and nanophotonics. However, in such applications, the fact that some chalcogenides accrue plasmonic properties in the transition from an amorphous to a crystalline state, i.e., the real part of their relative permittivity becomes negative, has gone somewhat unnoticed. Indeed, one of the most commercially important chalcogenide compounds, germanium antimony telluride (Ge2:Sb2:Te5 or GST), which is widely used in rewritable optical and electronic data storage technologies, presents this behavior at wavelengths in the near-ultraviolet to visible spectral range. In this work, we show that the phase transition-induced emergence of plasmonic properties in the crystalline state can markedly change the optical properties of sub-wavelength-thickness, nanostructured GST films, allowing for the realization of non-volatile, reconfigurable (e.g., color-tunable) chalcogenide metasurfaces operating at visible frequencies and creating opportunities for developments in non-volatile optical memory, solid state displays and all-optical switching devices.

The continuous development of electron devices towards the trend of “More than Moore” requires functional diversification that can collect data (sensors) and store (memories) and process (computing units) information. Considering the large occupation proportion of image data in both data center and edge devices, a device integration with optical sensing and data storage and processing is highly demanded for future energy-efficient and miniaturized electronic system. Two-dimensional (2D) materials and their heterostructures have exhibited broadband photoresponse and high photoresponsivity in the configuration of optical sensors and showed fast switching speed, multi-bit data storage, and large ON/OFF ratio in memory devices. In addition, its ultrathin body thickness and transfer process at low temperature allow 2D materials to be heterogeneously integrated with other existing materials system. In this paper, we overview the state-of-the-art optoelectronic random-access memories (ORAMs) based on 2D materials, as well as ORAM synaptic devices and their applications in neural network and image processing. The ORAM devices potentially enable direct storage/processing of sensory data from external environment. We also provide perspectives on possible directions of other neuromorphic sensor design ( e.g ., auditory and olfactory) based on 2D materials towards the future smart electronic systems for artificial intelligence.

This study investigates the optical, dielectric, and structural properties of novel perovskite-type ferroelectric ceramics, specifically Bi-doped (Ba 0.8 Sr 0.2 )(Ti 0.85 Zr 0.15 )O 3 nanoparticles, synthesized via the solid-state method. The materials were doped with Bi at the A-site with compositions of x = 0.03 and 0.05. X-ray diffraction (XRD) analysis confirmed that all samples crystallize in a cubic structure with the space group Pm3m. Dielectric measurements revealed a decrease in permittivity with increasing frequency, with notable transitions at 180 K and 170 K for x = 0.03 and x = 0.05, respectively. These findings are indicative of potential applications in energy storage where temperature stability is critical. Raman spectroscopy at room temperature corroborated the dielectric observations, showing peak broadening and reduced intensity with increasing temperature, particularly for the x = 0.05 composition. While photoluminescence spectroscopy and quantum yield measurements were not performed, the observed optical properties at room temperature suggest potential for application in optical devices. The combination of favorable dielectric characteristics, stable performance across temperature ranges, and promising optical properties underscores the versatility and optical devices applications of these Bi-doped perovskite ceramics in energy storage systems and ferroelectric memory devices. This study highlights the significant improvements in material performance achieved through Bi doping, contributing to the advancement of materials with specialized applications.

In antiquity, civilizations employed stone carvings and knotted quipu cords for information preservation. Modern telecommunications rely on optical fibers - silica glass strands engineered for light transmission - yet their capacity as archival media remains untapped. This study explores a novel fiber Bragg grating (FBG) configuration exhibiting thermally programmable memory effects for optical data storage. Capitalizing on temperature-dependent spectral characteristics, we demonstrate finite spectral tuning through controlled thermal annealing, achieving irreversible spectral modifications via a light-induced stress mechanism analogous to the Kovacs memory effect in glassy materials. The engineered dual-dip FBG architecture enables multiplexed wavelength encoding, functioning simultaneously as a thermal history recorder and laser-writable data medium - mirroring the information knots of ancient quipu devices. This optical quipu concept pioneers one-dimensional photonic memory technology, opening new avenues for optical fiber applications in the information age. This work introduces a dual-dip fiber Bragg grating (FBG) with thermally programmable memory. Leveraging light-induced stress and thermal annealing, it enables irreversible spectral tuning—mimicking the Kovacs effect. The FBG serves as a laser-writable, multiplexed optical data storage medium and thermal history recorder.

Phase-change materials are suitable for data storage because they exhibit reversible transitions between crystalline and amorphous states that have distinguishable electrical and optical properties. Consequently, these materials find applications in diverse memory devices ranging from conventional optical discs to emerging nanophotonic devices. Current research efforts are mostly devoted to phase-change random access memory, whereas the applications of phase-change materials in other types of memory devices are rarely reported. Here we review the physical principles of phase-change materials and devices aiming to help researchers understand the concept of phase-change memory. We classify phase-change memory devices into phase-change optical disc, phase-change scanning probe memory, phase-change random access memory, and phase-change nanophotonic device, according to their locations in memory hierarchy. For each device type we discuss the physical principles in conjunction with merits and weakness for data storage applications. We also outline state-of-the-art technologies and future prospects.

We propose an atomic grating based on an electromagnetically induced transparency phenomenon that switches between zeroth-order diffraction to a distinct higher-order diffraction pattern by driving a planar gaseous medium of a four-level tripod ( ⋔ ) atoms with three laser beams: modulation of standing wave control beam propagating nearly perpendicular to the planar medium, while vortex and weak plane probe beams directed perpendicular to the medium. We numerically investigate the behavior of the amplitude, phase modulations, and probe field diffraction intensities of different orders by the variation of the field detunings and orbital angular momentum number of the composite vortex light beam. Specifically, in the off-resonant case, the interplay between a square lattice of the control and an additional spatial variation of the vortex beam allows the emergence of higher diffraction orders and variable gain due to double transparency windows in this complex optical system. We believe that our proposed scheme might be useful in optical memory devices via the storage of information to diffraction orders of the atomic grating.