3D Data Storage Research Articles

Multiphoton‐And SHG‐Active Pyrimidine‐Based Liquid Crystalline Thin Films Toward 3D Optical Data Storage

AbstractAn original asymmetric achiral pyrimidine core molecule, with long carbon chains on one side and a coumarin fragment on the other, is designed. This advanced molecular structure enabled the spontaneous emergence of crystalline and liquid crystalline thin films with strong 2nd harmonic generation (SHG) without any corona polishing process or tedious deposition techniques. Moreover, pin‐pointed multiphoton absorption in the liquid crystalline phase effectively switches off the SHG signal locally and permanently, underlining its interest in 3D data storage. This prototypical material, which can be fully addressed by NLO processes, multiphoton writing, and SHG reading, paves the way for the development of efficient flexible materials for 3D optical data storage.

A Single-Shot Technique for Measuring Broadband Two-Photon Absorption Spectra in Solution.

Applications involving two-photon activation, including two-photon fluorescence imaging, photodynamic therapy, and 3D data storage, require precise knowledge of the two-photon absorption (2PA) spectra of target chromophores. Broadband pump-probe spectroscopy using femtosecond laser pulses provides wavelength-dependent 2PA spectra with absolute cross sections, but the measurements are sometimes complicated by cross-phase modulation effects and dispersion of the broadband probe. Here, we introduce a single-shot approach that eliminates artifacts from cross-phase modulation and enables more rapid measurements by avoiding the need to scan the time delay between the pump and the probe pulses. The approach uses counterpropagating beams to automatically integrate over the full interaction between the two pulses as they cross. We demonstrate this single-shot approach for a common 2PA reference, coumarin 153 (C153), in three different solvents using the output from a Yb:KGW laser. This approach provides accurate 2PA cross sections that are more reliable and easier to obtain compared with scanning pump-probe methods using copropagating laser beams. The single-shot method for broadband two-photon absorption (BB-2PA) spectroscopy also has significant advantages compared with single-wavelength measurements, such as z-scan and two-photon fluorescence.

Photon Upconversion Cooperates with Downshifting in Chiral Systems: Modulation, Amplification, and Applications of Circularly Polarized Luminescence

AbstractCircularly polarized luminescence (CPL)‐active materials are increasingly recognized for their potential applications such as 3D imaging, data storage, and optoelectronic devices. Typically, CPL materials have required high‐energy (HE) photons for excitation to emit low‐energy (LE) circularly polarized light, a process known as downshifting CPL (DSCPL). However, the emergence of upconverted CPL (UCCPL), where the absorption of multi LE photons results in the emission of a single HE photon with circular polarization, has recently attracted considerable attention. This minireview highlights the intricate relationship between upconversion and CPL phenomena. During upconversion, the dissymmetry factor (glum) value can be improved in certain systems. Additionally, the integration of both LE and HE photons in upconversion‐downshifting‐synergistic systems offers avenues for dual‐excitation or dual‐emission CPL functionalities. More in detail, the emerging UCCPL based on various photon upconversion mechanisms and their synergy with DSCPL are introduced. Additionally, several examples that demonstrate the applications of UCCPL are presented to highlight the future opportunities.

Photon Upconversion Cooperates with Downshifting in Chiral Systems: Modulation, Amplification, and Applications of Circularly Polarized Luminescence.

Circularly polarized luminescence (CPL)-active materials are increasingly recognized for their potential applications such as 3D imaging, data storage, and optoelectronic devices. Typically, CPL materials have required high-energy (HE) photons for excitation to emit low-energy (LE) circularly polarized light, a process known as downshifting CPL (DSCPL). However, the emergence of upconverted CPL (UCCPL), where the absorption of multi LE photons results in the emission of a single HE photon with circular polarization, has recently attracted considerable attention. This minireview highlights the intricate relationship between upconversion and CPL phenomena. During upconversion, the dissymmetry factor (glum) value can be improved in certain systems. Additionally, the integration of both LE and HE photons in upconversion-downshifting-synergistic systems offers avenues for dual-excitation or dual-emission CPL functionalities. More in detail, the emerging UCCPL based on various photon upconversion mechanisms and their synergy with DSCPL are introduced. Additionally, several examples that demonstrate the applications of UCCPL are presented to highlight the future opportunities.

PRESERVATION THROUGH DIGITIZATION - STANDARDIZATION IN DOCUMENTATION OF BUILD CULTURAL HERITAGE USING CAPTURING REALITY TECHNIQUES AND HERITAGE/HISTORIC BIM METHODOLOGY

Abstract. Building Information Modelling (BIM) is an established approach in the construction industry that enables efficient collaboration between stakeholders and facilitates project management. However, when it comes to historical buildings, the application of BIM can be demanding due to the complex nature of these projects. Although BIM Uses in the construction sector are well-documented (Penn State University, 2013) and we are surrounded by amazing technologies, we do not yet have standardized international workflows on how to use those state-of-the-art techniques with Cultural Heritage Assets (Bruno and Roncella, 2019). Standardizing Cultural Heritage (CH) metric documentation and Heritage/Historic Building Information Modeling (HBIM) is challenging since each CH asset needs different information throughout the whole life cycle of the monument - both their physical and non-physical attributes, such as historical and cultural characteristics. Additionally, every work carried out on CH, such as knowledge acquisition, restoration, adaptation, etc., requires specific data inputs. Although there are guidelines books that offer some general proposals, they represent the maximum effort towards standardization. As a result, the field of HBIM has emerged as a relatively new area of scientific research that focuses on the digital representation of CH assets.This research aims to develop a working method and templates for procurement workflow standardization that will facilitate the documentation of historic buildings and heritage assets in coordination with relevant historic preservation authorities for the BIM use case - asset register. The use of various measurement methods, the registration of captured point clouds, and the transfer of geometry to a BIM-compliant 3D information model and sustainable data storage are important aspects of this project.

Mid-Wave Infrared Snapshot Compressive Spectral Imager with Deep Infrared Denoising Prior

Although various infrared imaging spectrometers have been studied, most of them are developed under the Nyquist sampling theorem, which severely burdens 3D data acquisition, storage, transmission, and processing, in terms of both hardware and software. Recently, computational imaging, which avoids direct imaging, has been investigated for its potential in the visible field. However, it has been rarely studied in the infrared domain, as it suffers from inconsistency in spectral response and reconstruction. To address this, we propose a novel mid-wave infrared snapshot compressive spectral imager (MWIR-SCSI). This design scheme provides a high degree of randomness in the measurement projection, which is more conducive to the reconstruction of image information and makes spectral correction implementable. Furthermore, leveraging the explainability of model-based algorithms and the high efficiency of deep learning algorithms, we designed a deep infrared denoising prior plug-in for the optimization algorithm to perform in terms of both imaging quality and reconstruction speed. The system calibration obtains 111 real coded masks, filling the gap between theory and practice. Experimental results on simulation datasets and real infrared scenarios prove the efficacy of the designed deep infrared denoising prior plug-in and the proposed acquisition architecture that acquires mid-infrared spectral images of 640 pixels × 512 pixels × 111 spectral channels at an acquisition frame rate of 50 fps.

3D palatal rugae recognition based on Fractional Fourier Transform

Following a major disaster, most of the biological characteristics of the victims are typically destroyed, which increases the difficulty of forensic identification. However, palatal rugae cannot be easily destroyed owing to its unique location characteristics, owing to which it has become a new type of biological feature used in forensic identification under special environments. This study proposes a new method of 3D palatal rugae recognition which uses fractional Fourier transform (FRFT). The isometric slicing operation is first used to simplify the complexity of the algorithm and improve the efficiency of the 3D data storage and expression. FRFT is the used to extract the fractional domain features of the profile images obtained by slicing the 3D palatal rugae, and the support vector machine recursive feature elimination (SVM-RFE) method is used for feature selection in the fractional domain. The use of FRFT increases the number of the palatal rugae features extracted from the time-frequency domain, and can improve the effectiveness of feature extraction. The recognition accuracy rate of the proposed 3D palatal rugae recognition system can reach up to 97.8%. The proposed method meets the requirements of 3D palatal rugae recognition, and can help in performing rapid forensic identification. The method proposed in this study is useful in reducing the dependence on human experts and promoting the digitization of a forensic identification system based on palatal rugae.

Giant enhancement of the transverse magneto-optical Kerr effect based on the Tamm plasmon polaritons and its application in sensing

The giant enhancement of the transverse magneto-optical Kerr effect (TMOKE) is investigated. It is achieved by depositing a multilayer structure in the form of alternating magnetic and nonmagnetic dielectric film on a metallic mirror supported by a dielectric substrate. The results show that near perfect TMOKE is realized owing to the Tamm plasmon polaritons (TPPs) excited between the multilayer structure and the metallic mirror, which is confirmed by illustrating the distributions of the magnetic field at resonance. Besides, the potential applications of the giant enhancement of the TMOKE on the sensing are also illustrated in the last. It is believed that the proposed structures in this work are promising for the development of 3D imaging, data storage and novel sensors with high sensitivity.

Phase‐change memory based on matched Ge‐Te, Sb‐Te, and In‐Te octahedrons: Improved electrical performances and robust thermal stability

AbstractPhase‐change memory (PCM) has been developed for three‐dimensional (3D) data storage devices, posing huge challenges to the thermal stability and reliability of PCM. However, the low thermal stability of Ge2Sb2Te5 (GST) limits further application. Here, we demonstrate PCM based on In0.9Ge2Sb2Te5 (IGST) alloy, showing 180°C 10‐years data retention, 6 ns set speed, one order of magnitude longer life time, and 75% reduced power consumption compared to GST‐based device. The In can occupy the cationic positions and the In‐Te octahedrons with good phase‐change properties can geometrically match well with the host Ge‐Te and Sb‐Te octahedrons, acting as nucleation centers to boost the set speed and enhance the endurance of IGST device. Introducing stable matched phase‐change octahedrons can be a feasible way to achieve practical PCMs.image

Reversible 3D optical data storage and information encryption in photo-modulated transparent glass medium

Transparent glass has been identified as a vital medium for three-dimensional (3D) optical information storage and multi-level encryption. However, it has remained a challenge for directly writing 3D patterning inside a transparent glass using semiconductor blue laser instead of high-cost femtosecond laser. Here, we demonstrate that rare earth ions doped transparent glass can be used as 3D optical information storage and data encryption medium based on their reversible transmittance and photoluminescence manipulation. The color of tungsten phosphate glass doped with rare earth ions change reversibly from light yellow to blue upon alternating 473 nm laser illumination and temperature stimulation, resulting in the reversible luminescence modulation. The information data could be repeatedly written and erased in arbitrary 3D space of transparent glass, not only showing the ability of the excellent reproducibility and storage capacity, but also opening opportunities in information security. The present work expands the application fields of luminescent glass, and it is conducive to develop a novel 3D data storage and information encryption media.

Multi-photon absorption properties of semiconducting nanomaterials

Multiphoton absorption (MPA) is a nonlinear optical process that involves simultaneous absorption of two or more photons by a material to promote its ground state to an excited state. Multiphoton absorption promises many important applications such as multi-dimensional fluorescence imaging, three dimensional (3D) data storage. Physical and chemical properties of nanometer sized semiconductor materials change drastically due to quantum size effect. Combination of both multiphoton absorption and quantum effects will be an interesting study. Multiphoton absorption of semiconducting nanomaterials is an exciting phenomenon which promotes many important applications. This paper reviews multi-photon absorption properties of different kinds of semiconducting nanomaterials starting from chalcogenide-based nanomaterials to perovskites nanomaterials and their applications in various fields.

New bis-photochromic compounds based on diarylimidazoles: Synthesis and multistimuli-responsive optical properties.

Three new bis-photochromic molecules containing two 4,5-diarylimidazole units were synthesized and characterized. We investigated their photophysical properties and pH response characteristics in acetonitrile solutions and polymethylmethacrylate (PMMA) membranes. All compounds displayed significant pH responses for the imidazole ring in the molecular structure, which could be potentially used as pH probes. Under ultraviolet light, these compounds show photochromism and 'turn-off' fluorescence properties either in solution or in PMMA film. The mechanism of this phenomenon may be due to photoisomerization, that is the conversion of the 4,5-diarylimidazole units open-ring form to the closed-ring form. Moreover, such systems as logic gates, high density (3D) data storage systems and optical equivalents of field-effect transistors are considered necessary for optical computing.

Three dimensional range geometry and texture data compression with space-filling curves.

This paper presents a novel method to effectively store three-dimensional (3D) data and 2D texture data into a regular 24-bit image. The proposed method uses the Hilbert space-filling curve to map the normalized unwrapped phase map to two 8-bit color channels, and saves the third color channel for 2D texture storage. By further leveraging existing 2D image and video compression techniques, the proposed method can achieve high compression ratios while effectively preserving data quality. Since the encoding and decoding processes can be applied to most of the current 2D media platforms, this proposed compression method can make 3D data storage and transmission available for many electrical devices without requiring special hardware changes. Experiments demonstrate that if a lossless 2D image/video format is used, both original 3D geometry and 2D color texture can be accurately recovered; if lossy image/video compression is used, only black-and-white or grayscale texture can be properly recovered, but much higher compression ratios (e.g., 1543:1 against the ASCII OBJ format) are achieved with slight loss of 3D geometry quality.

Photoinitiation and Inhibition under Monochromatic Green Light for Storage of Colored 3D Images in Holographic Polymer-Dispersed Liquid Crystals.

Holographic photopolymer composites have garnered a great deal of interest in recent decades, not only because of their advantageous light sensitivity but also due to their attractive capabilities of realizing high capacity three-dimensional (3D) data storage that is long-term stable within two-dimensional (2D) thin films. For achieving high performance holographic photopolymer composites, it is of critical importance to implement precisely spatiotemporal control over the photopolymerization kinetics and gelation during holographic recording. Though a monochromatic blue light photoinitibitor has been demonstrated to be useful for improving the holographic performance, it is impractical to be employed for constructing holograms under green light due to the severe restriction of the First Law of Photochemistry, while holography under green light is highly desirable considering the relatively low cost of laser source and high tolerance to ambient vibration for image reconstruction. Herein, we disclose the concurrent photoinitiation and inhibition functions of the rose bengal (RB)/N-phenylglycine (NPG) system upon green light illumination, which result in significant enhancement of the diffraction efficiency of holographic polymer-dispersed liquid crystal (HPDLC) gratings from zero up to 87.6 ± 1.3%, with an augmentation of the RB concentration from 0.06 × 10-3 to 9.41 × 10-3 mol L-1. Interestingly, no detectable variation of the ϕ1/2kp/kt1/2, which reflects the initiation efficiency and kinetic constants, is given when increasing the RB concentration. The radical inhibition by RBH• is believed to account for the greatly improved phase separation and enhanced diffraction efficiency, through shortening the weight-average polymer chain length and subsequently delaying the photopolymerization gelation. The reconstructed colored 3D images that are easily identifiable to the naked eye under white light demonstrate great potential to be applied for advanced anticounterfeiting.

Assessing the workflow for regional-scale 3D geologic modeling: An example from the Sullivan time horizon, Purcell Anticlinorium East Kootenay region, southeastern British Columbia

We have developed a regional-scale 3D geologic model, highlighting the Mesoproterozoic Sullivan time horizon (approximately 1470 Ma) throughout the Purcell Anticlinorium in the East Kootenay region. This 3D geospatial model of the region is constrained with an extensive surface and subsurface database of stratigraphic, structural, and geophysical observations distributed throughout the study area. This modeling exercise was conducted over a four-year period from 2011 to 2015 in which several iterations of the model were produced. The final model includes what is locally referred to as the Lower-Middle Aldridge stratigraphic contact (LMC), a map unit at the very top of the lower Aldridge Formation where the Sullivan world-class Pb-Zn-Ag deposit is located. Local mineral exploration initiatives focus on this key exploration target horizon, which is now modeled in 3D. The regional LMC model provides a much needed geospatial reference used to characterize and understand sedimentary exhalative, a type of ore deposit (SEDEX) ore systems as well as a key 3D exploration target. Developing regional 3D geologic models for orogenic interiors such as the Purcell region, and older shield regions is a challenge. This is largely due to data sparsity at depth, lack of standards for 3D data collection, storage, integration, and interpretation practice. Current algorithms use only a partial set of available observational or knowledge constraints and exist in workflows that do not allow for complicated geologic event histories. We have mitigated some of these challenges with a new implicit algorithm (SURFE), applied in this Purcell case study, to estimate major regional faults and horizons through variably distributed and clustered data. These modeled geologic elements are then fed into the SKUA structural and stratigraphic workflow to produce the volumetric model. Reflection on the general 3D modeling workflow for these regional situations highlights the need for embedding more knowledge constraints into the process.

Metal-Organic Frameworks as Platforms for Functional Materials.

Discoveries of novel functional materials have played very important roles to the development of science and technologies and thus to benefit our daily life. Among the diverse materials, metal-organic framework (MOF) materials are rapidly emerging as a unique type of porous and organic/inorganic hybrid materials which can be simply self-assembled from their corresponding inorganic metal ions/clusters with organic linkers, and can be straightforwardly characterized by various analytical methods. In terms of porosity, they are superior to other well-known porous materials such as zeolites and carbon materials; exhibiting extremely high porosity with surface area up to 7000 m(2)/g, tunable pore sizes, and metrics through the interplay of both organic and inorganic components with the pore sizes ranging from 3 to 100 Å, and lowest framework density down to 0.13 g/cm(3). Such unique features have enabled metal-organic frameworks to exhibit great potentials for a broad range of applications in gas storage, gas separations, enantioselective separations, heterogeneous catalysis, chemical sensing and drug delivery. On the other hand, metal-organic frameworks can be also considered as organic/inorganic self-assembled hybrid materials, we can take advantages of the physical and chemical properties of both organic and inorganic components to develop their functional optical, photonic, and magnetic materials. Furthermore, the pores within MOFs can also be utilized to encapsulate a large number of different species of diverse functions, so a variety of functional MOF/composite materials can be readily synthesized. In this Account, we describe our recent research progress on pore and function engineering to develop functional MOF materials. We have been able to tune and optimize pore spaces, immobilize specific functional groups, and introduce chiral pore environments to target MOF materials for methane storage, light hydrocarbon separations, enantioselective recognitions, carbon dioxide capture, and separations. The intrinsic optical and photonic properties of metal ions and organic ligands, and guest molecules and/or ions can be collaboratively assembled and/or encapsulated into their frameworks, so we have realized a series of novel MOF materials as ratiometric luminescent thermometers, O2 sensors, white-light-emitting materials, nonlinear optical materials, two-photon pumped lasing materials, and two-photon responsive materials for 3D patterning and data storage. Thanks to the interplay of the dual functionalities of metal-organic frameworks (the inherent porosity, and the intrinsic physical and chemical properties of inorganic and organic building blocks and encapsulated guest species), our research efforts have led to the development of functional MOF materials beyond our initial imaginations.

Comparative Analysis of 3D Data Storage Format in Intelligent Systems and Virtual Reality

В данной статье проанализированы наиболее популярные форматы для хранения трехмерной геометрии, которые играют важную роль в развитии новых интеллектуальных систем, например, форматы: .3DS, .MAX, .OBJ, .FBX, .WRL и .STL. Анализ 3D форматов был проведен методом сравнения объема, занимаемого на жестком диске, низкополигональной и высокополигональной моделей изделия и коэффициентов сжатия при использовании алгоритма LZSS. На основе проведенного исследования 3D форматов, описывается их сфера использования, совместимости с различными операционными системами, формулируются основные сравнительные характеристики. В статье определен наиболее эффективный и оптимальный 3D формат для хранения моделей в задачах, связанных с интеллектуальными системами и технологиями виртуальной реальности. Данная статья будет полезной, прежде всего, для проектировщиков систем, базис которых основывается на технологии виртуальной реальности.

Two-Photon Absorbing Molecules as Potential Materials for 3D Optical Memory

In this review, recent advances in two-photon absorbing photochromic molecules, as potential materials for 3D optical memory, are presented. The investigations introduced in this review indicate that 3D data storage processing at the molecular level is possible. As 3D memory using two-photon absorption allows advantages over existing systems, the use of two-photon absorbing photochromic molecules is preferable. Although there are some photochromic molecules with good properties for memory, in most cases, the two-photon absorption efficiency is not high. Photochromic molecules with high two-photon absorption efficiency are desired. Recently, molecules having much larger two-photon absorption cross sections over 10,000 GM (GM= 10−50 cm4 s molecule−1 photon−1) have been discovered and are expected to open the way to realize two-photon absorption 3D data storage.

Integration of data resulting from various types of lumbar spine examinations

Lower back region and lumbar spine in particular can be measured and evaluated with a number of methods and from a number of viewpoints. Measurement method depends essentially on the objective. Tests can be static or dynamic, can target detection of pathological conditions or just evaluate persons with no specific complaints, can be performed once or repeatedly (as follow-up series). Authors present the development of a complex system that records and stores examination data of various types and formats (image, video, numeric, text, etc.). Moire-based virtual imaging method and a mechano-optical handheld scanning device, developed at the Department of Mechatronics, Optics and Engineering Informatics, Budapest University of Technology and Economics (BME MOGI) are used for static examinations. Dynamic tests can be performed with the system (developed also at BME MOGI) that gives 3D information with the help of depth sensors. Conventional examination results, such as static pressure maps obtained with a podoscope, x-ray images, and results of manual measurements (distances, angles, muscle ductility) provide useful information one by one. Measurement protocols help systematic data collection. Integrating measurement results from previously mentioned methods, and utilizing 3D visualization, data storage and processing, increases the amount of information compared to individual pieces of data, and previously unknown connections can be revealed. The integrated data acquisition and processing system helps organization and systematic processing of data stored in various (file) formats, type (text, image, numerical, etc.) and information content. DOI: 10.17489/biohun/2013/1/13

Use of 3D photography in complex-wound assessment

To review the evidence to support three-dimensional (3D) photographic imaging in wound care and undertake a feasibility evaluation of one device in the clinical environment. A literature review was undertaken of the role of stereophotogrammetry in wound care.Subsequently, a 3D imaging and data storage system was selected and evaluated in two representative case studies within the clinical environment of the Royal Centre for Defence Medicine. The review suggested that 3D imaging has the potential to provide more accurate data on which to base treatment decisions. In practice, the device was found to be relatively easy to operate and sufficiently robust to handle the demands of clinical practice. However, the high initial cost of the unit and the time taken to download images to the database meant that its benefits were limited to more complex wound types. Three-dimensional photography has the potential to play a role in management options;however, current technical issues limit its potential and the incorporation of a highly defined image (similar to that of a standard digital 2D photograph) within its 3D representation would make it more powerful.