With the rapid development of internet, internet of things, cloud computing and artificial intelligence, human society has entered the age of Big Data. In the face of such a large amount of data, how to store it safely and reliably, green and energy-saving, long life and low cost has become an important issue. Traditional optical storage technology has been unable to meet the practical requirements, and needs to be modified and upgraded, or even developed a new generation of storage technology. So far, a variety of prototypes based on the optical storage principle have been successfully developed and applied in engineering. The optical storage technology has been improved continuously and is being applied and used gradually. This paper first briefly introduces the development history of optical storage technology, and then lists eight types of optical storage technologies with industrial prospects in detail, summarizes their principles and development status, and discusses their technical features and prospects as Big Data storage media. Finally, the future development trend of optical storage technology is prospected in order to provide technical reference for the development of optical storage technology in the era of Big Data.

Though optical data storage technology has attractive potential because of its long storage lifetime and low energy consumption, current optical data storage technologies are challenged by their capacity and dentistry for big data application. Dual-beam super-resolution optical data storage technology exhibits obvious advantage in ultra-high capacity and density due to the overcoming of optical diffraction limit. This work illuminates the key problems in the industrialization of dual-beam super-resolution optical data storage technology, and discusses some basic solutions to these obstacles.

The digital data created by human being grows exponentially in time. Conventional magnetic storage technologies are difficult to meet this challenge. It means that new storage technologies with higher capacity, higher security and longer storage time should be developed to meet the challenge in information age. With the invention of lasers and the rapid development of nanotechnology, multidimensional optical data storage based on the polarization and wavelength dependent responses of gold nanorods was demonstrated to be capable of meeting these requirements. We will review the recent progresses about five-dimensional optical data storage and multilevel storage utilizing disorder gold nanorod from the structured matter point of view and super resolution storage from the structured light point of view, respectively. We also provide outlooks for how to further increase the capacity of the five dimensional optical data storage and our future prospective of this technology.

Volume holographic storage technology has the advantages of high storage density, huge data capacity, parallel read and write, fast transmission speed and so forth. In Big Data era, this method has great potential to meet its needs of low cost and low storage density. Holographic storage devices fabricated by photopolymer materials have attracted wide attention because of its several advantages, such as low cost, light weight, and high commercial value. The excellent performance of photopolymer applied on volume holographic storage is introduced in this paper.

By recording the polarization grating formed by the interference of two polarized lights, polarization holography can store the information in polarization sensitive materials. In contrast to traditional holography, polarization holography owns many unique properties, for instance, utilizing the long-neglected polarization information and increasing storage capacity. This paper first briefly introduced the development of polarization holography, the tensor-based holographic theory and some of its inferences. Then the further applications of polarization holography in high density data storage are briefly overviewed.

The development of optical holographic data storage technology in the past 50 years is reviewed in this paper. With the continuous development of key devices and materials, optical holographic data storage technology is becoming more and more mature. At present, in the era of Big Data, the demands for data storage density and data transfer rate are greater than ever before. Optical holographic data storage has become a potential candidate for the next generation of data storage technology because of its advantages of superhigh storage capacity, superfast data transfer rate, and superlong storage life. The coaxial holographic storage system will become the cornerstone of further practicality of holographic storage technology because of its compact structure, simple operation and strong compatibility. Meanwhile, new phase modulated holographic data storage system is becoming the research hotspot. The new round of rapid development has arrived.

Human beings are entering a Big Data era, which has significantly boosted the current digital economy and society. But in reality, all current data storage technologies and mediums can only store less than half of what we generate, which means most of the data will be forcibly lost if without breakthrough in high-capacity storage technologies. However, Ernst Abbe set a fundamental barrier that limits the smallest feature size of a recording voxel to approximately half of the wavelength. Alternatively, this limitation could be overcome by implementing multiplex technology. In this review, techniques employed various multiplex dimensions such as 3D space, polarization and wavelength are briefly introduced. Especially, we highlight the development history, current state of the art and urgent challenges of five-dimensional optical data storage based on laser-induced nanogratings.

With the rapid development of Big Data and artificial intelligence, emerging information technology compels dramatically increasing demands on data information storage. At present, conventional magnetization-based information storage methods generally suffer from technique challenges raised by short lifetime and high energy consumption. Optical data storage technology, in comparison, is well known for its advantages of low energy consumption and high security. However, the disc capacity of optical data storage technology inevitably gets stuck in the physical fundamental barrier-optical diffraction limit. How to break optical diffraction barrier and improve the resolution of optical storage system, thereby increasing the data storage capacity of the optical storage system is the key to incorporating optical storage technology with information technology trend such as big data and cloud computing. In this review, we present the principle of optical storage techniques beyond diffraction-limited and recent progress in high capacity optical data storage, including far field super-resolution three dimensional optical (3D) storage techniques (such as two-photon absorption-based process and saturation stimulated emission depletion fluorescence-inspired approaches) and near field super-resolution two dimensional (2D) optical storage techniques (such as near field scanning probe methods, solid immersion lens approaches, and super-resolution near-field structure methods). Eventually, the here-and-now problems confronted by the super-resolution optical data storage and future development of optical storage technology towards ultra-high capacity optical disc based on optical super-resolution techniques are discussed.

Based on the principle of the volume holographic data storage, the technologies and its main systems of holographic data storage are reviewed. The principle, system structure and coding method of the collinear holographic data storage system are introduced and analyzed. In the absence of mature phase encoding principle, two kinds of phase encoding of phase-modulated collinear holographic data storage systems are analyzed and evaluated. These two phase encoding methods effectively complement the possible methods of phase encoding in holographic storage. The pairs-phase-encoding improves the code rate and reduces the error rate compared with traditional encoding. Moreover, a multilevel complex amplitude modulated collinear holographic storage system is introduced, which can efficiently reduce material consumption and increases storage capacity. Moreover, its system performance is evaluated. Consequently, more reasonable coding method, appropriate modulation and suppression of noise, are still urgent problems in the researching of holographic data storage technology.

Compared with magnetic switching by an external magnetic field or by a heat-assisted manner, all-optical switching (AOS) can complete the switching process within 100 ps, which has attracted extensive attention from researchers. Among the magneto-optical materials which can realize AOS, the ferrimagnetic GdFeCo has the ability to realize single-shot AOS and possesses great potential in all-optical magnetic storage. In this paper, a microscopic three-temperature model (M3TM) is utilized to simulate the AOS process of GdFeCo, which is also demonstrated experimentally, under the excitation of a single laser pulse based on the heating effect. By using this M3TM, the AOS dynamics and the final magnetization states of GdFeCo induced by single laser pulses with different energy and pulse widths are calculated and analyzed concretely. Compared with the atomic spin model and the Landau- Lifshitz-Bloch (LLB) model, M3TM provides a more concise time-varying expression of the magnetization of GdFeCo and explicitly addresses the dissipation of angular momentum after the laser-pulse excitation, which enables faster calculations of the heat-induced magnetization dynamics in magneto-optical materials with large areas.

The synthesis process of doped photopolymer has a significant impact on its properties. The tradional optimization method for the synthesis process of doped photopolymers depends on experimental parameters and experimental experience. A method for quantitatively monitoring and optimization of the synthesis process of doped photopolymers by absorption spectrum is presented in this paper. The absorption spectra of samples in different steps of the preparation are measured and analyzed. The change rule of the absorption spectra in preparation process is revealed. Quantitative monitoring of the progress and the synthesis rate of photopolymers could be realized by the proposed method. This method brings new possibility to quantitative optimization in the preparation process of doped photopolymers.

In order to improve the reliability of optical storage data, this paper proposes an error correction methodology in optical storage system which is based on redundant recovery code technology, it relates to the field of optical disc data storage. The methodology consists of two opposite processes – recording and retrieving. While recording data, firstly, splitting user data into blocks and encoding it with redundancy recovery code; next, organizing data blocks as UDF (universal disc format) file system; finally, modulating and encoding UDF file system data as strip group according to the optical disc physical format and recording it into optical disc. In contrast, while retrieving data, demodulating and decoding data strip group which is stored in optical disc at first; later, following UDF file system format to resume user data; in the end, verifying user data with redundant recovery code and return it to user. The methodology is compatible with the standard optical disc file system, and improves the fault tolerance efficiently. Original blu-ray physical format signal error rate is 4.1×10-13, the signal error rate can be down to 7.4×10-24 after redundancy recovery code check.

Optical discs can reliably preserve massive data for long-term in low-cost. When querying these accumulative data, it is necessary to quickly obtain the query results, and to seek the physical location of the corresponding optical disc. To this end, it demands each disc have a unique identifier in both the cyber and physical worlds, make massive data be managed effectively, conveniently, and credibly. This paper designs a batch-disc automatic identification system, which integrates common optical disc recorders, printers, and cameras, automatically to print physical label and to burn logical identification on each disc. Consider that each commodity component has its own internal independent timing control and a specific external interface. This study designed and developed a customized mechanical structure, as well as a global software scheduling mechanism to coordinate physical behavior and logical control. The experimental results show that the system can continuously identify 200 discs at once, averaging 2 minutes per disc.