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1.
The advantages of read-only storage is the predominance of optical recording
relative to magnetic and other rewritable methods. Multilevel (ML) read-only
technology has been a trend to improve the data capacity and transfer rate. Based on
the principle and coding method of ML, this paper demonstrates some ML read-only
recording methods, of which a new ML read-only recording is developed. This
recording method integrates amplitude modulation achieved by the reaction mechanism
of physics and chemistry of photoresist with the run-length-limited technology. The
discs can be achieved using standard photoresist mastering and replication
techniques with great compatibility to conventional binary read-only discs. 相似文献
2.
Pit Depth and Width Modulation Multilevel Run-Length Limited Read-Only Optical Storage 总被引:1,自引:0,他引:1 下载免费PDF全文
When the techniques of integrating the variation of the conventional DVD,the high-density multilevel run-length pit depth and width simultaneously are adopted to limited read-only optical storage method is achieved. The dynamic range of readout signal is greatly enlarged in comparison with keeping one parameter varied, and the recording levels number can be obviously increased. The discs can be manufactured using standard photoresist mastering and replication techniques with great compatibility to conventional binary read-only discs. Experimental results show that eight-level read-only optical disc can be realized and the capacity can be increased to 20 GB. 相似文献
3.
Two unconventional nano-aperture light sources, an L-shaped nano-aperture source and a 3D nano-aperture source for high-density optical data storage, are numerically investigated. With incidence of a Gaussian beam, the spot size of the Poynting vector coupled into the recording medium is 130 × 175 nm^2 for the L-aperture and 120 × 135 nm^2 for the 3D nano-aperture. The quantitative analyses indicate that the unconventional nanoaperture sources can provide enough power density to record marks in the commercial recording medium. It is feasible to use a laser diode with a nano-aperture as an active nanometer light source for high-density optical data storage. 相似文献
4.
An innovative multilevel read-only recording method is proposed. In this method, a short pit/land is deliberately inserted to the original land/pit. This modifies the wave-shape of readout signM. Taking the wave-shape as the symbol of level detection, a signal wave-shape modulation (SWSM) multilevel method is realized. This method is carried out and validated on the DVD read-only manufacture and readout system. A capacity of 15 GB can be expected, and a bit error rate of 10-4 is achieved. The capacity can meet the demand of high definition movie publication. This method also provides a potential multi-level solution for other storage formats and systems. 相似文献
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7.
Effects of recording wavelength on the recently proposed (Sasaki, 2008) three-dimensional vector holograms, in which the optical anisotropy is three-dimensionally modulated, are presented experimentally and theoretically. The polarization states of the interference light are three-dimensionally modulated due to both the polarization interference and optical anisotropy in the recording medium. These spatial distributions of the polarization states and the resulting diffraction properties in the three-dimensional vector holograms are strongly dependent on the recording wavelength. Theoretical consideration based on the finite-difference time-domain (FDTD) method reveals the mechanism of the optical characteristics of the three-dimensional vector holograms recorded by various kinds of light sources with different wavelengths. 相似文献
8.
多阶游程存储是一种不改变光学系统而显著提高光存储容量和数据传输率的新方法.介绍了光致变色多阶游程存储原理和实验系统.提出了基于光致变色原理的多阶游程存储数学模型,该模型反映了记录符反射率与曝光功率、曝光时间之间的非线性关系,并在此基础上确定了光致变色多阶游程存储的写策略.基于650nm光致变色材料进行了4阶游程存储的动态实验.结果表明,实验中采用的650nm光致变色材料可用于多阶游程存储,采用的写策略能够有效地使记录信道线性化,利于采用适合线性系统的信号处理方法.
关键词:
多阶游程
光致变色
光存储
写策略 相似文献
9.
A solid immersion lens combined with a conical dielectric tip exhibits good resolution and efficiency in reading and recording data marks on optical storage media. We demonstrate a combination aperture that produces ~200-nm full-width 1/e(2) spot size and achieves 50% optical efficiency in an edge-scan experiment. A comparison of recording with the combination aperture, with an unmodified solid immersion lens, and with a far-field system is made. 相似文献
10.
Investigation of Near-Field Imaging Characteristics of Radial Polarization for Application to Optical Data Storage 总被引:4,自引:0,他引:4
Wan-Chin Kim No-Cheol Park Yong-Joong Yoon Hyun Choi Young-Pil Park 《Optical Review》2007,14(4):236-242
Radially polarized incident light can generate a more confined longitudinal electric field on a focal plane in near-field
(NF) optics than focusing circularly polarized light. Using this phenomenon, it is feasible to reduce beam spot size on storage
media to increase the areal density of optical data storage. A radially polarized beam generates a beam spot which is 20%
more confined on the 1st surface of medium than that of circularly polarized light. However, the peak intensity of total electric
field sharply decreases and its transverse component is much more dominant inside the media stack. This confirms that radially
polarized optics can be a candidate not for an NF recording system but for an NF read-only memory (ROM) system. Potentially,
the results could be useful to understand the effect of radial and circular polarizations inside and outside medium for various
applications of NF optics. 相似文献
11.
We have developed a near-field optical probe that uses a triangular metallic plate with a three-dimensionally tapered apex as a light source for thermally assisted magnetic recording. Numerical analysis using a finite-element method shows that the size of the optical spot generated at the apex is 15 nm x 20 nm, and the efficiency (defined as the ratio between the power of the optical near field at the surface of the recording medium and that of the incident light) is 15% when the incident light is focused by a lens with a numerical aperture of 0.8. The metallic plate was fabricated on the surface of a quartz slider and used for writing marks on a phase change recording medium. The marks were observed with a scanning electron microscope, and we confirmed that marks with a diameter of 40 nm were successfully written on the medium. 相似文献
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13.
The problems related to noise that arise during recording and reconstruction of holograms used in optical data storage or in massive optical interconnection systems are quite similar and can be analyzed in order to improve the quality of the images that these optical systems provide. In this paper, we will analyze noise in cases in which several coherent object waves are simultaneously stored in a phase recording material in a way that allows us to obtain information about the relationship that exists between the recording material and the number of waves that are being stored. The material used in this study is Agfa Gevaert 8E75 HD holographic film processed with a rehalogenating—type bleach bath without a fixation step. Additionally, we show experimentally that it is possible to holographically store more than 400 waves at the same time (in a coherent fashion) using the same storage geometry, with a signal-to-noise ratio larger than 20 and an average diffraction efficiency of 15%. 相似文献
14.
Z.B. Qin Y.Q. Wen Y.L. Shang Y.L. Song Y.Z. Wan 《Applied Physics A: Materials Science & Processing》2007,87(2):277-280
In this paper, organic thin films of a nonlinear optical (NLO) material ((E)-1-ferrocenyl-2-(l-methyl-4-pyridiniumyl) ethylene
iodide) were prepared by a vacuum deposition method. The typical I–V curve of the film exhibits a favorable room-temperature
bistability. Further recording experiments have been performed with a scanning tunneling microscope, which confirmed that
the thin film of the donor–π–acceptor NLO material could certainly be applied for nanoscale data storage. The average size
of the recorded marks is about 1.5 nm. Mechanism analyses suggest that the formation of the recording dots is due to the local
change of electrical property of the thin film, and the intermolecular charge transfer induced by an electric field is proposed
as the reason for the change.
PACS 68.37.-d; 73.61.-r; 81.16.Rf; 68.37.Ef; 73.61.Ph 相似文献
15.
New photopolymerizable holographic recording material based on polyvinylalcohol and 2-hydroxiethylmethacrylate (HEMA) 总被引:2,自引:0,他引:2
S. Blaya L. Carretero R.F. Madrigal M. Ulibarrena A. Fimia 《Applied physics. B, Lasers and optics》2002,74(6):603-605
We have developed a new polyvinylalcohol-based photopolymeric holographic recording material. The recording is obtained by
the copolymerization of acrylamide and 2-hydroxiethylmethacrylate (HEMA). Diffraction efficiencies near 70% are obtained with
exposures of ≈65 mJ/cm2 in materials of 110-μm thickness. The addition of HEMA increases the thickness of the film, which results in improved storage
capacity for holographic optical storage.
Received: 7 March 2002 / Published online: 2 May 2002 相似文献
16.
近场光学在高密度存储中的应用 总被引:3,自引:0,他引:3
近场光学在高密度存储方面有着很大的潜力 ,使得近场光学存储近年来得到了广泛的关注。近场光学存储具有高密度大容量及可以利用许多已有相关技术等优点 ,预计近场光学存储密度能达到 7Gbit/ cm2 ;它还可以采用硬盘驱动器中的空气悬浮磁头技术和磁光存储中的技术等 ,使近场存储的研究和开发更加迅速。目前 ,近场光学存储主要有三种方案 :探针型方案、超分辨率近场结构、固体浸没透镜方案 ,这三种方案都是通过不同的方法缩小记录光斑来实现高密度的存储。介绍了近场光学存储的原理、研究现状及材料 ,并对三种近场存储方案的实现方法和发展概况作了详细的阐述 ,分析了这三种方案的优缺点 相似文献
17.
光聚物全息光盘记录方法和光路的优化 总被引:3,自引:1,他引:2
提出了适用于光聚物厚膜盘状高密度全息存储的角度空间复用相结合的存储方法。研究了光路设置对记录容量和密度的影响 ,分析和计算表明 :对全息光盘光聚物全息存储介质来说 ,新方法可以获得比空间角度复用存储方法高近一个数量级的存储容量和密度 ,当使用平面波做参考光、介质内参物光入射角度在 32°时是获得最大存储容量和密度的最佳设置 ;对 5 0 0 μm厚的光聚物介质 ,存储密度可达到 42bit/ μm2 ,用CD ROM同样大小的全息光盘 ,在其相同的有效记录面积上 ,其总容量可以达到 40 0Gbit,表明新方法是实用化光聚物盘状全息存储比较理想的方法。 相似文献
18.
Holographic data storage is being widely studied for the purpose of developing next-generation large optical memories. A prospective
use of this type of memory is in building image archives in large-scale data centers. In particular, demand for energy conservation
at data centers, and therefore for holographic data storage, is growing. In holographic data storage, interference between
bits occurs owing to wave aberration in the optical system, shrinkage of the medium, and crosstalk noise from neighboring
holograms during multiplex recording; as a result of the interference, the reproduced image deteriorates and the bit error
rate (BER) increases. In this study, to reduce the BER in both off-axis-type recording and coaxial-type recording, a two-dimensional
finite impulse response (FIR) filter is applied to a reproduced image that has been recorded by angle multiplex recording
and shift multiplex recording. First, for the optimization of the FIR filter coefficients, the linear minimum mean square
error (LMMSE) method is applied; this method optimizes the coefficients by reducing the BER. Furthermore, for evaluating the
optimization performance of the LMMSE method, the optimization performance is compared with that of the real-coded genetic
algorithm (RCGA), which has the capability to search a wide range of coefficients. The optimization by the LMMSE method has
been found to be excellent for off-axis-type recording but not for coaxial-type recording. It is speculated that this is because
of the brightness irregularity in the reproduced image, resulting from crosstalk. On the other hand, a marked reduction in
the BER is observed using the RCGA, despite the brightness irregularity. In this study, the effectiveness of the LMMSE method
for signals recorded by coaxial-type recording, in which large brightness irregularity is expected, is examined using automatic
gain control (AGC). It is found that the application of AGC reduces the BER even in the case of coaxial-type recording. 相似文献
19.
Theoretical and experimental analyses of recording mark microstructures in signal waveform modulation optical disc 下载免费PDF全文
In this paper,we propose a dynamic mastering process model for signal waveform modulation (SWM) optical disc.To form the ideal microstructures and solve the problems in the SWM master manufacturing process,we use this model to simulate the three-dimensional mark profiles in the SWM read-only disc.The simulated micro-patterns of recording pits and lands are employed to optimize the writing strategy and provide a quantitative basis for manufacturing the sub-pits and sub-lands.The simulation mark profiles are compared with the experimental ones,which are produced with the optimized writing strategy parameters.Comparison results demonstrate that the simulated profiles are highly consistent with the actual ones. 相似文献
20.
本文以Philips VP—700为对象,利用琼斯矩阵法对只读武光盘光学系统以及光学元件进行了详细分析,提出了在只读式光盘机上实现光磁信息处理的理论模型。根据这一模型,本文进而建立了实验系统。实验结果表明理论分析正确。 相似文献