Three-dimensional Optical Storage Research Articles

Achieving ultra-high-density two-dimensional optical storage through angle resolved LSPR arrays: A case study of square array

With the development of optical storage technology, there is an increasing amount of research based on multi-dimensional high-density storage. Compared to two-dimensional storage, three-dimensional storage can achieve ultra-high-density optical storage by stacking two-dimensional storage layer by layer on the vertical direction. However, three-dimensional storage has problems such as high manufacturing costs, large processing errors and complex readout processes. Therefore, it is of great interest to study the implementation of two-dimensional ultra-high-density optical storage. Plasmonic is one of the most promising technologies to realize ultra-high-density, low maintenance media, and long-life optical storage. In this work, nano-scaled rotary gold square two-dimensional arrays were designed to achieved ultra-high-density optical storage. For angle-resolved localized surface plasmon resonance (LSPR) nano-arrays, when the rotation angle of 1-unit gold square nano-structure is 2°, the storage density was 12.79 GB/cm2, which was 53.29 times of a single-layer Blu-ray disk. By varying the shape and size of the nano-structure, higher two-dimensional storage densities could be achieved. Research results showed that, with proper design, the density of two-dimensional optical storage can match or exceed that of three-dimensional optical storage. This study demonstrates the potential of LSPR-based two-dimensional nanostructures for optical storage, providing another possibility for ultra-high density and high-resolution optical storage.

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.

Single-shot photon recording for three-dimensional memory with prospects of high capacity.

Femtosecond laser-induced modification in the glass has drawn considerable interest due to its widespread superiority in the applications of three-dimensional optical storage. In this Letter, we report that a single pulse could be used in optical memory with super-high writing speed. The photoluminescence image and spectrum indicate that one pulse-induced permanent photoreduction of Sm3+ to Sm2+ in Sm3+-doped sodium aluminoborate glass can be achieved. Consequently, strong emission contrast is obtained, which is used for optical storage. By regulating the fabrication conditions, the fluorescent diameter could be controlled to approximately 800 nm, which demonstrates the feasibility in super-high density optical storage. Besides, multi-layer information is successfully inscribed. The proposed technique of single-pulse writing holds great potential for optical memory with high speed and huge capacity.

Fabrication of multilayered structure of silver nanorod arrays for plasmon memory

In recent years, many devices utilizing plasmon resonance have been studied. Among the various plasmonic devices, the next generation of plasmon memory is expected to be a three-dimensional optical storage media. The plasmon memory is a three-dimensional structure in which a metal nanorod layer and a resin layer are stacked. This is expected to have more capacity than conventional optical storage media. Generally, metal nanostructures can be fabricated by using electron beam lithography, metal deposition, and lift-off processes. By repeating this process, the three-dimensional structure can be fabricated. However, because the electron beam lithography and metal deposition are conducted in a vacuum, the fabrication of plasmon memory requires considerable time. Thus, the productivity of the plasmon memory is very low. In our previous research, we developed a process that can be fabricated in ambient atmosphere by nanoimprint lithography (NIL) and silver ink instead of electron beam lithography and metal deposition. Using NIL, a high throughput nanopattern fabrication method, and silver ink, which can be used in ambient atmosphere, allows for highly efficient production of metal patterns. Thus, this process can shorten the time required compared to the usual process. Additionally, in order to operate as a plasmon memory, it is necessary to align the metal nanostructure for each layer. In this study, we developed an alignment mark suitable for NIL and metal nanostructure fabrication using silver ink. By positioning the alignment mark while looking through an optical microscope, the metal nanostructure was aligned and a three-layer silver patterned nanorod structure was fabricated. The misalignment was suppressed to 230nm in the vertical direction and 320nm in the lateral direction.

Cavity Light Bullets in Passively Mode-Locked Semiconductor Lasers.

We demonstrate the existence of stable three-dimensional dissipative localized structures in the output of a laser coupled to a distant saturable absorber. These phase invariant cavity light bullets are individually addressable and can be envisioned for three-dimensional optical information storage. An effective theory provides for an intuitive picture and allows us to relate their formation to the morphogenesis of static spatial autosolitons and temporal cellular patterns.

Research on synchronization of double bald of femtosecond laser three-dimensional optical storage system

Based CD/DVD servo technology and two-photon absorption technology, a CD/DVD compatible three-dimensional optical storage system is built. Double bald synchronization performance is tested using the direct method and indirect test method, test results show that under certain conditions, double bald synchronization errors are less than 2μm, which basically meets the requirements of double bald three-dimensional optical storage system, however, the double bald synchronization error is still relatively large, in order to the laser beam is focused onto the information point at the strongest intensity, the reader module circuit of three-dimensional optical storage system needs to be improved, so that we can get smaller synchronization error and obtain the better storage results

Creation of a three-dimensional super-resolution transversally polarized focal spot by 4π tight focusing of radially polarized vortex beams

The intensity profiles near the focus of a 4π high numerical aperture focusing configuration for two counter-propagating radially polarized hollow Gaussian (HG) vortex beams are examined numerically. Theoretical calculations manifest that, in contrast to the single-objective focusing system, a three-dimensional super-resolution focal spot with purely transverse polarization can be formed. Such an unusual pattern stems from combining the faultlessly destructive interference of the longitudinal component of the electric field with the constructive interference of the transverse components (azimuthal and radial components) created by the two counter-propagating radially polarized vortex beams, as well as benefits from the higher-order HG mode (e.g., n = 4) to govern the aspect ratio of the focal spot. Moreover, the tolerances on focusing performance for modest displacement from the center of the HG beams with different orders are researched in detail. We expect that such a three-dimensional super-resolution field with transverse polarization can be extensively used in super-resolution confocal microscopy and three-dimensional high-density optical storage.

Two-photon three-dimensional optical storage of a new pyrimidine photobleaching material

Two-photon three-dimensional high-density optical storage is an important method of optical storage. Based on two-photon absorption three-dimensional optical information storage principle of light-induced bleaching, the storage information is written and readout by using titanium sapphire femtosecond pulsed laser, the experiment of the storage information written and readout is carried out in a novel photobleaching material pyrimidines, six layers storage information is achieved, information point spacing is 4μm and the information layer spacing is 12μm. The signal strength information of six layers information is recognized using MATLAB software. And the experiment of the stability of the pyrimidine photobleaching material is carried out, experimental results indicate that the material has good stability. The experiments show that the pyrimidine photobleaching materials can be used for two-photon three-dimensional optical storage, which has laid a solid foundation for multi-layer high density and high density optical information storage materials research.

Two-Photon Three-Dimensional Optical Storage of a New Photobleaching Material

Two-photon three-dimensional optical data storage is an important method to realize high density storage and ultra-high density storage. This paper introduces the the basic principle of two-photon photobleaching optical storage, describes two-photon three-dimensional optical storage system and the absorption and fluorescence spectra of a new type of photobleaching materials BASF in detail, carries out the experimental study that two-photon information is written and read out against a new photobleaching material of BASF using femtosecond pulse laser wavelength is 800nm, and realize two layers of optical information storage, the information point spacing is 8μm and the interlayer distance is 15μm; two-layer information point signal strength is recognized using Recognition algorithm. The experiment proved that new photobleaching material of BASF can be used for two-photon three-dimensional optical storage, that has laid a solid foundation for the high-density and ultra-high density optical information storage materials research.

The Hardware and Software Design of Dual Pick-up Head Three-Dimensional Optical Storage System

Femtosecond laser two-photon three-dimensional optical data storage is an effective method for high capacity data storage. In this paper, system construction is analyzed in detail from hardware and software aspects for dual pick-up head three-dimensional optical storage systems. Three-dimensional optical storage system is conposed of the fluorescence reader module and the servo control module, firstly analyzes the read and write process of three-dimensional optical storage by 89c52 MCU controling from the hardware. Then, the software is analyzed in detail, the software consists of two parts: the lower computer software and PC software. lower computer software achieves communication and control related to hardware, PC software is used to facilitate the control of the experimental system. Two CPU control software is introduced, and controlling process of PC software control is analyzed in detail. These work has laid a solid foundation for the practical of three-dimensional optical storage technology.

Research on the Application of DVD Pick-Up Head in Three-Dimensional Optical Storage

Two-photon three-dimensional optical data storage is an effective method for high capacity data storage. Based on DVD pick-up head and two-photon absorption, two-photon three-dimensional optical disk storage system is built, and operating principle of the overall system is in detail. In the servo module of three-dimensional optical disk storage system, DVD circuit control board (MT1389SE) is conducted on three-point improvement: extract focus servo error signal and servo error signal, increase four communications interfaces，increase photoelectric detectors; the extraction of focus and track servo signal on reading and writing module is analyzed in detailed. The measured principles and methods of the voice coil motor characteristic curve of Sanyo DVD pick-up head (SF-HD60S) are analyzed in detailed by using dual-frequency laser interferometer, which can be well meet the layer selection requirements of three-dimensional optical storage. DVD pick-up head applied in three-dimensional optical storage overcomes the limitations of three-dimensional scanning stage, integrates with existing DVD servo technology, and lays a solid foundation for practical use of two-photon three-dimensional optical storage.

Femtosecond laser induced photoluminescence in poly(methyl methacrylate) and three-dimensional optical storage

We report on a femtosecond-laser induced photoluminescence (PL) in poly(methyl methacrylate) and its potential application to three-dimensional optical storage. Irradiation with a focused 800 nm, 1 kHz, 100 fs pulsed laser induced a strong PL change in UV–visible region. Absorption spectra and Fourier-transform infrared spectra before and after laser irradiation indicate the PL may result from the emissive oxidized products of photo-degradation reaction of PMMA. This makes it possible to read out the stored data by detecting the PL change. The pulse energy threshold of the light-induced PL change of PMMA is found to be at ∼2 μJ/pulse and the optimal recording energy is ∼3 μJ/pulse. A ten-layer pattern inside the bulk sample recorded by tightly focusing a pulsed laser beam was read out by a reflection-type fluorescent confocal microscope, which detected the emission in visible range as the signal. High-contract fluorescent images with a much higher signal-to-noise ratio were obtained without crosstalk in comparison with the ordinary reflection mode.

三维光存储中折射率失配引起的球差补偿

For the compensation of the spherical aberration induced by refractive index mismatch in three-dimensional optical storage,the model of the optical storage is established,and the expression of the wavefront phase aberration function is achieved induced by refractive index with the storage depth.The phase aberration function is spred with Zernike polynomials.Under reading method of two-photon fluorescence and one-photon confocal fluorescence,the relation of the intensity with storage depth is obtained:under uncompensating the spherical aberration induced by refractive index mismatch,storage fluorescence intensity falls to zero in the storage depth of 200 μm;under compensating the first-order spherical aberration,the downtrend of storage fluorescence intensity with the storage depth is improved;under compensation the second-order spherical aberration,the storage fluorescence intensity varies little in the storage depth of 1 mm.And the method of the aberration compensation is analyzed in detail.

Three-Dimentional Optical Storage Medium Using Arranged Nano-spheres

In this study, we have developed a multi-layered optical storage medium with nano-spheres as the recording medium. We made a three-layered medium of spheres and thereby realized a three-dimensional high-density optical storage system. Using a reflection confocal optical system, we read out clock signals from the medium. The system records data and reconstructs it jitter-free.

Three-Dimensional Multilayered Optical Memory Using Two-Photon Induced Reduction of Au$^{3+}$ Doped in PMMA

We developed a rhodamine-B and Au3+ doped PMMA medium for three-dimensional multilayered optical storage. Using the quenching of rhodamine-B by Au3+ ions and the two-photon induced reduction of Au3+ ions to the Au nanoparticle, the developed medium can record and store binary bit data in the form of a fluorescent patterns inside a thick medium. The recorded fluorescent pattern is read out three-dimensionally by using pick-up which incorporates confocal laser scanning fluorescent microscopy

Complex amplitude distribution for compensation of refractive index mismatch on 3D optical storage recording system

The complex amplitude distribution which can compensate for the spherical aberration caused by mismatch on interface between recording material and immersion material (air) on three-dimensional optical storage system is derived analytically and numerically. Comparison between two approaches is made. It is also shown how the depth of recording layer and position of reference plane are related to the phase distribution at reference plane and how the mismatch can be resolved by using a pure phase element.

Three-Dimensional Optical Storage with Photosensitive Fluorescent Material

We propose a three-dimensional optical storage medium in which a confocal laser-scanning microscopy is applied for multilayer fluorescence readout. The contrast of signal intensity for inside and outside of the pit can reach 71%.

Three-Dimensional Multi-Layered Bit-Oriented Optical Storage

Three-dimensional multi-layered optical storage is one of the most promising methods that break the limitation of recording density in optical storage. It stores the bit information onto the multilayered recording planes inside the thick recording medium and realizes the tremendous large recording capacity. This paper describes the recording/reading principles, the systems, and the materials suitable for three-dimensional multi-layered memory. We also present the experimental results that using photochromic organic materials and rhodamine-B-doped and Au(III)-doped PMMA for recording medium.

Polymeric nanostructured material for high-density three-dimensional optical memory storage

The unique properties of a polymer photonic crystal are examined with respect to applications as a medium for high-density three-dimensional optical data storage media. The nanocomposite material was produced from core-shell latex particles, in which the latex cores contained dye-labeled polymer. Nonfluorescent latex shells were attached to the core particles. Upon annealing, the close-packed core-shell particles formed a nanostructured material with the fluorescent particles periodically embedded into the optically inert matrix in a hexagonal close-packed structure. A two-photon laser scanning microscope was used to write bits of information into the material by photobleaching the optically sensitive particles and, under much lower fluence, read out the resulting image. Relative to conventional homogeneous storage media, the nanostructured periodic material is shown to increase the effective optical storage density by at least a factor of 2 by spatially localizing the optically active region and imposing an optically inactive barrier to cross-talk between bits. This polymer photonic crystal has the potential to dramatically improve performance further through the improved capabilities to optimize the photochemical processes and more fully exploiting the periodic nature of the information domains in the image processing.

Singlebeam 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-substituted 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 are desirable when using a readout laser power smaller than 5 mW.