Ostensibly perpetual optical data storage in glass with ultra-high stability and tailored photoluminescence

Long-term optical data storage(ODS)technology is essential to break the bottleneck of high energy consumption for information storage in the current era of big data.Here,ODS with an ultralong lifetime of 2×10^(7)years is attained with single ultrafast laser pulse induced reduction of Eu^(3+)ions and tailoring of optical properties inside the Eu-doped aluminosilicate glasses.We demonstrate that the induced local modifications in the glass can stand against the temperature of up to 970 K and strong ultraviolet light irradiation with the power density of 100 kW/cm^(2).Furthermore,the active ions of Eu^(2+)exhibit strong and broadband emission with the full width at half maximum reaching 190 nm,and the photoluminescence(PL)is flexibly tunable in the whole visible region by regulating the alkaline earth metal ions in the glasses.The developed technology and materials will be of great significance in photonic applications such as long-term ODS.

Optical tape for high capacity three-dimensional optical data storage

In this Letter,a new approach of optical tape for high capacity multilayer data storage is proposed.We show that a length of 5 cm and width of 2 cm of soft and transparent optical tape can be used for two-photon three-dimensional bit data storage.We successfully demonstrate writing and reading of six layers of data storage with a transverse bit separation of 2μm and an axial separation of 2.5μm in a tetraphenylethylene-doped photobleaching polymer.The fluorescence intensity is insensitive to the storage depth of the photopolymer matrix.Thus,the optical tape that we put forward in the experiment can help people realize true large data storage in the future,like magnetic tape.This method significantly paves a novel way for solving big data storage problems.

Near-perfect fidelity polarization-encoded multilayer optical data storage based on aligned gold nanorods

Encoding information in light polarization is of great importance in facilitating optical data storage(ODS)for information security and data storage capacity escalation.However,despite recent advances in nanophotonic techniques vastly en-hancing the feasibility of applying polarization channels,the data fidelity in reconstructed bits has been constrained by severe crosstalks occurring between varied polarization angles during data recording and reading process,which gravely hindered the utilization of this technique in practice.In this paper,we demonstrate an ultra-low crosstalk polarization-en-coding multilayer ODS technique for high-fidelity data recording and retrieving by utilizing a nanofibre-based nanocom-posite film involving highly aligned gold nanorods(GNRs).With parallelizing the gold nanorods in the recording medium,the information carrier configuration minimizes miswriting and misreading possibilities for information input and output,respectively,compared with its randomly self-assembled counterparts.The enhanced data accuracy has significantly im-proved the bit recall fidelity that is quantified by a correlation coefficient higher than 0.99.It is anticipated that the demon-strated technique can facilitate the development of multiplexing ODS for a greener future.

Unconventional phase transition of phase-change-memory materials for optical data storage

Recent years, optically controlled phase-change memory draws intensive attention owing to some advanced applications including integrated all-optical nonvolatile memory, in-memory computing, and neuromorphic computing. The light-induced phase transition is the key for this technology. Traditional understanding on the role of light is the heating effect. Generally, the RESET operation of phase-change memory is believed to be a melt-quenching-amorphization process. However, some recent experimental and theoretical investigations have revealed that ultrafast laser can manipulate the structures of phase-change materials by non-thermal effects and induces unconventional phase transitions including solid-to-solid amorphization and order-to-order phase transitions. Compared with the conventional thermal amorphization,these transitions have potential superiors such as faster speed, better endurance, and low power consumption. This article summarizes some recent progress of experimental observations and theoretical analyses on these unconventional phase transitions. The discussions mainly focus on the physical mechanism at atomic scale to provide guidance to control the phase transitions for optical storage. Outlook on some possible applications of the non-thermal phase transition is also presented to develop new types of devices.

Decoding the future:opportunities and challenges in next-generation optical data storage[Invited]

The ongoing quest for higher data storage density has led to a plethora of innovations in the field of optical data storage.This review paper provides a comprehensive overview of recent advancements in next-generation optical data storage,offering insights into various technological roadmaps.We pay particular attention to multidimensional and superresolution approaches,each of which uniquely addresses the challenge of dense storage.The multidimensional approach exploits multiple parameters of light,allowing for the storage of multiple bits of information within a single voxel while still adhering to diffraction limitation.Alternatively,superresolution approaches leverage the photoexcitation and photoinhibition properties of materials to create diffraction-unlimited data voxels.We conclude by summarizing the immense opportunities these approaches present,while also outlining the formidable challenges they face in the transition to industrial applications.

Y_(3)Al_(5)O_(12):Ce^(3+) fluorescent ceramic for optical data storage

A kind of optical data storage medium based on electron-trapping materials,Y_(3)Al_(5)O_(12):Ce^(3+)fluorescent ceramic,was developed by vacuum sintering technology.The medium shows sufficiently deep traps[1.67 and 0.77 eV].The properties of trap levels were researched by thermoluminescence curves,and the optical storage mechanism based on Ce^(3+)ion doping was proposed.More importantly,the data can be written-in by 254 nm UV light,and readout by heating[300°C].This work expands the application fields of fluorescent ceramics,and it is expected to promote the development of electron-trapping materials.

Single-beam two-photon three-dimensional optical storage in a pyrryl-substituted fulgide photochromic material

We introduce a high-density three-dimensional optical data storage approach by using a pyrryl-sub-stituted fulgide photochromic material with a method of single-beam two-photon recording and fluorescence confocal readout. The detailed information about the photochromic material and the experimental setup are presented. The experiments about multi-layered recording and readout are carried out with a 100-μm-thick transparent photochromic material film. The results show that the lateral resolution is better than 1 μm, and the longitudinal resolution is about 3 μm. Besides, the readout times for the recorded data aredesirable when using a readout laser power smaller than 5 mW.

Optical storage arrays: a perspective for future big data storage

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.

Multi-carbazole derivatives for two-photon absorption data storage:Synthesis,optical properties and theoretical calculation

Two novel quadrupolar organic compounds, 3-(4-((E)-2-(9-butyl-9H-carbazol-6-yl) vinyl)styryl)-9-propyl-9H-carbazole (BCSPC) and 3-(3-(3-((1E)-2-(4-((E)-2-(3-(3,5-bis(9-butyl-9H-carbazol-6-yl)phenyl)-9-butyl-9H-carbazol-6-yl)vinyl)phenyl) vinyl)-9-butyl-9H-carbazol-6-yl)-5-(9-butyl-9H-carbazol-6-yl)phenyl)-9-butyl-9H-carbazole (BCPBC), with different conjugated arms, have been designed and synthesized. Their one-and two-photon absorption (TPA) and excited fluorescence properties have been experimentally investigated. The two-photon absorption cross-sections of two compounds were estimated by two-photon excited fluorescence technique using 200 fs, 76 MHz, Ti:sapphire laser, which are 22 and 154 GM for BCSPC and BCPBC, respectively. The optimal excitation wavelengths are 780 nm for both BCSPC and BCPBC. A data recording experiment proved the potential application of the materials.

Experimental investigation of parallel optical data storage using pyrrylfulgide photochromic material

The optical storage characteristics of a new kind of organic photochromic material棗pyrrylfulgide were experimentally investigated in the established parallel optical data storage system. Using the pyrrylfulgide/PMMA film as a photon-mode recording medium, micro-images and encoded binary digital data were recorded, readout and erased in this parallel system. The storage density currently reaches 3?07 bit/cm2. The recorded information on the film can be kept for years in darkness at room temperature.

Miniaturized volume holographic optical data storage and correlation system with a storage density of 10 Gb/cm^3

The general idea of holographic optical data storage (HODS) is briefly introduced. Based on the recent advances of HODS, the key techniques and the challenges of HODS are discussed. Some new techniques are proposed to improve the system. A miniaturized volume holographic data storage and correlation system is presented. It can achieve a density of 10 Gb/cm3 and a fast correlation recognition rate of more than 2000 images per second. It shows the attracting potential advantages over other conventional storage meth- ods in the information storage as well as information proc- essing.

High density collinear holographic data storage system

Holographic data storage system （HDSS） has been a good candidate for a volumetric recording technology, due to their large storage capacities and high transfer rates, and have been researched for tens of years after the principle of holography was first proposed. However, these systems, called conventional 2-axis holography, still have essential issues for commercialization of products. Collinear HDSS, in which the information and reference beams are modulated co-axially by the same spatial light modulator （SLM）, as a new read/write method for HDSS are very promising. With this unique configuration, the optical pickup can be designed as small as DVDs, and can be placed on one side of the recording media （disc）. In the disc structure, the preformatted reflective layer is used for the focus/tracking servo and reading address information, and a dichroic mirror layer is used for detecting holographic recording information without interfering with the preformatted information. A 2-dimensional digital page data format is used and the shift-multiplexing method is employed to increase recording density. As servo technologies are being introduced to control the objective lens to be maintained precisely to the disc in the recording and reconstructing process, a vibration isolator is no longer necessary. Collinear holography can produce a small, practical HDSS more easily than conventional 2-axis holography. In this paper, we introduced the principle of the collinear holography and its media structure of disc. Some results of experimental and theoretical studies suggest that it is a very effective method. We also discussed some methods to increase the recording density and data transfer rates of collinear holography.

A rapid response photochromic diarylethene material for rewritable holographic data storage

A novel diarylethene,namely 4,5-(2,5-dimethyl thiophene) phthalimide,was synthesized and successfully introduced to rewritable holographic data storage.Upon the alternative illumination of UV and visible light(>400 nm),this compound underwent rapid,reversible inter-conversion between colorless open-ring isomer and yellow-green ring-closed form in both solution and polymethyl methacrylate(PMMA) film.Subsequently,we investigated the characteristics of volume homographic recording of the diarylethene-doped PMMA film(1 m thick).The maximum refractive index modulation(0.87‰) of the film during recording could be reached within just 120 s which gave the ability of fast recording.The high quality reconstruction after 50 write/erase cycles demonstrated its excellent fatigue-resistance and high resolution.All those results indicated that this molecule was a reliable fast write/erase holographic storage material.

聚集诱导发光分子在双光束超分辨光存储中的潜在应用

聚集诱导发光分子因其高效的发光性质而被广泛应用于生物成像、光波导和电致发光等领域,但在光信息存储领域还鲜有研究。与其他光存储材料相比,聚集诱导发光分子的局域密度变化会引发荧光强度的变化,这在光存储领域是一个显著优点。该文针对聚集诱导发光分子的特性,讨论了该类分子在超分辨光存储领域的可能应用方式,以及需要解决的关键问题。

基于核函数非线性变换的无线光通信网络数据安全存储方法

为控制数据安全存储时间,开展基于核函数非线性变换的无线光通信网络数据存储方法的设计研究。数据发射端通过发送数据检测序列,在通信链路中动态检测数据的完整性,并在保证数据完整性和安全性的前提下进行数据存储。为处理低维无线光通信网络数据,采用核函数进行非线性变换,将数据映射到高维空间,并使用主成分分析法对高维空间中的核矩阵进行降维,以提取数据属性特征。为实现安全存储,使用云存储环境将数据包拆分成多个片段,并进行分布式加密安全存储。实验结果表明,利用设计方法能够有效缩短存储时间。

磁光电混合存储系统在数据安全方面的技术分析

随着信息和数据库技术的不断发展,以及各行业积累了越来越多的历史数据,如何安全高效地存储重要历史数据成为摆在各行业面前的一大难题。磁光电混合存储系统是将磁盘、光盘和固态硬盘/卡三类存储媒体相结合,且通过软件管理对外提供统一存储空间的存储系统。通过对蓝光存储技术的特点以及其在数据存储的安全方面的保护机制,来分析磁光电混合存储技术,可以有效提高数据存储的可靠性、完整性,同时还能在防泄漏、防篡改等多方面提供多层保护,有效提升数据存储的安全性。

含偶氮苯光学活性侧基聚合物研究进展

综述了含偶氮苯光学活性侧基聚合物近年来的发展概况 ,介绍了多种聚合体系的类型。由于偶氮苯光于活性侧基的存在 ,使得这些聚合物具有光致变色性、非线性光学活性、光学各向异性等光学性能 ,在光信息存储材料、非线性光学材料、液晶材料、光电子器件、生物分子活性光调控、纳米技术等诸多领域都有广泛的应用。

电子俘获材料在光存储技术中的应用

阐述了电子俘获光存储技术原理 ,进行了图像写 /读 /擦除及图像加 /减等实验 ,探讨了电子俘获光存储中的动力学机制 ,研究了电子俘获材料中读出光、写入光和发射光三者之间的关系。实验表明 ,电子俘获材料以其写 /读 /擦速度快、存储密度高以及无限的读写循环寿命等优点 ,在光存储、光信息处理领域具有非常广阔的应用前景。

高密度光存储实现途径分析

随着光存储技术的发展,如何提高光盘存储密度备受关注。应用信道分析的方法,讨论了影响存储密度的因素和参量,提出光学系统分辨本领及光存储机理是其中最重要的因素。分别从缩短波长、增大数值孔径、超分辨以及缩小记录点、复用记录点及增加存储维度等角度总结了提高系统分辨能力、改变存储机理以提高光盘存储密度的途径。

光电子技术及其进展

综述了光电子学的产生及其发展 ,提出了光电子技术的几个发展方向和研究热点。对各种新型激光器、硅基光电子技术、有机聚合物光电子材料、光互连、光计算技术、大容量光存储。