共查询到20条相似文献,搜索用时 31 毫秒
1.
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
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
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
2.
3.
Approximated Vector Diffraction Theory for Readout Signal of Multi-Level Run-Length-Limited Discs
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Multi-level run-length-limited read-only optical storage is a kind of high density storage method. The width and height of recording marks are varied with different levels, which is the key technology for the optical storage. Then the readout signal of these discs with complex recording marks is computed by vector analysis method, it is very hard and time-consuming. Approximated vector computation combines the convenience of scalar method and precision of vector method, which is effective for multi-level run-length-limited read-only optical storage. 相似文献
4.
Xinmiao Lu Yiqun Wu Yang Wang Jingsong Wei 《Applied Physics A: Materials Science & Processing》2012,108(4):765-769
Bismuth-doped antimony-based (Sb100?x Bi x , x=2.46) thin films were presented as a functional mask for super-resolution readout of read-only memory (ROM). The pit size of the ROM was 390?nm, and super-resolution readout was realized on a dynamic tester with laser wavelength of 780?nm and the numerical aperture of the focusing objective lens of 0.45. The carrier-to-noise ratio (CNR) of 22?dB, readout threshold power of 0.8?mW and super-resolution readout cycles of 2×104 was achieved. The influence of film thickness and readout power on CNR was investigated. The reflectivity and transmittance of the film with different temperature at wavelength of 780?nm were detected, and the super-resolution mechanism of the bismuth-doped antimony-based thin films as the functional mask layer was discussed. 相似文献
5.
超分辨薄膜是一种能够实现突破光学衍射极限的功能薄膜,它在超分辨近场光存储技术中起到至关重要的作用。采用磁控溅射共溅的方式制备了Ag掺杂一定量Si的超分辨复合薄膜,测试了其作为掩膜层的超分辨光盘读出性能,并获得了最佳的薄膜制备条件,即当Ag溅射功率为55 W,Si为95 W,溅射时间为80s,薄膜厚度为39nm时,超分辨光盘的读出信号载噪比(CNR)最高为28dB。用X射线光电子能谱测量了上述薄膜的组成,用扫描电子显微镜观察了薄膜微区形貌,并用椭圆偏振光谱仪测量了薄膜的光学常数和厚度。超分辨复合薄膜的读出机理可以用Ag的散射型机理解释。光盘在持续读出10万次以后读出信号基本没有下降。 相似文献
6.
Sb-Bi alloy flms are proposed as a new kind of super-resolution mask layer with low readout threshold power. Using the Sb-Bi alloy film as a mask layer and SiN as a protective layer in a read-only memory disc, the superresolution pits with diameters of 380 nm are read out by a dynamic setup, the laser wavelength is 780 nm and the numerical aperture of pickup lens is 0.45. The effects of the Sb-Bi thin film thickness, laser readout power and disc rotating velocity on the readout signal are investigated. The results show that the threshold laser power of super-resolution readout of the Sb-Bi mask layer is about 0.5 m W, and the corresponding carrier-to-noise ratio is about 20 dB at the film thickness of 50nm. The super-resolution mechanism of the Sb-Bi alloy mask layer is discussed based on its temperature dependence of reflection. 相似文献
7.
We describe the three-dimensional holographic optical disc system for application as read-only memory. Several systems design issues are discussed including imaging optics, storage density, readout rate, and the alignment servo system. We demonstrate 40 bits/m2 surface density and pixel-matched holographic data readout from a 12 cm disc spinning at 600 RPM. 相似文献
8.
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
9.
A prototype of X-ray imaging device based on triple Gas Electron Multiply detector is studied,which has an effective gain up to 105 and can be used in high rate X-rays imaging.The precise method of micro–strip readout is designed for X-rays localization, and the crate controller of high–speed SCSI interface is applied for the data acquisition.The test results show that the position resolution of measurement system is less than 90μm and the stability of its effective gain is better than 1% under the X-ray flux of 105Hz/mm2. 相似文献
10.
11.
Effect of Spectroscopy Amplifier Parameter on Identification of Light Charged Particles by Pulse Shaping Analysis Method
下载免费PDF全文
![点击此处可从《中国物理C(英文版)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
WANG Jin-Chuan XI Hong-Fei GUO Zhong-Yan ZHAN Wen-Long ZHU Yong-Tai ZHOU Jian-Qun LOU Guan-Hua SU Hong 《中国物理C(英文版)》1993,17(1):69-77
The pulse shaping analysis method is applied to identify the light charged particles emitted from 12C(46.7/MeV/u)+58Ni reaction by using the CsI(T1) scintillator detector with photodiode readout.In the experiment,it is found that the particle identification greatly depends on the choice of spectroscopy amplifier shaping time constant.The problem is investigated on the basis of Laplace transformation method.The experimental phenomena have been successfully explanined. 相似文献
12.
Total ionizing dose effects of Si^+ ion implanted thermal oxides are studied by 10keV x-ray irradiation. Photoluminescence (PL) method is engaged to investigate nanostructures of samples. Ar^+ implanted samples are also studied by the same way to provide a comparison. The results show that Si^+ implantation following with high temperature annealing can significantly reduce the radiation induced flatband shift, which is caused by net posi- tive charge accumulation in oxides. This reduction is attributed to the formation of Si nanoscale structures. Ar^+ implantation is also found to reduce the radiation induced flatband shift, while it is different that the reduction with Si^+ implantation shows little dependence on implant dose of Ar^+ ions. This is explained by possible increase of recombination centres. 相似文献
13.
To improve the tracking servo performance, a novel signal waveform multi-level (SWML) read-only disc realized on the digital versatile disc (DVD) platform is presented. The characteristic of the differential phase detection (DPD) signal of the SWML read-only disc is analyzed both in theory and experiment. The amplitude of the DPD signal of the SWML read-only disc in an open tracking servo loop is about 2/3 of that of the DVD read-only disc. The uniformity and symmetry of the DPD signal of the SWML read-only disc are similar to those of the DVD read-only disc and better than the former multi-level run-length limited (ML-RLL) read-onlv disc. 相似文献
14.
Polarization readout analysis for multilevel phase change recording by crystallization degree modulation
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Four different states of Si15Sb85 and Ge2Sb2Te5 phase change memory thin films are obtained by crystallization degree modulation through laser initialization at different powers or annealing at different temperatures. The polarization characteristics of these two four-level phase change recording media are analyzed systematically. A simple and effective readout scheme is then proposed, and the readout signal is numerically simulated. The results show that a high-contrast polarization readout can be obtained in an extensive wavelength range for the four-level phase change recording media using common phase change materials. This study will help in-depth understanding of the physical mechanisms and provide technical approaches to multilevel phase change recording. 相似文献
15.
16.
A two-dimensional optical storage (TwoDOS) format with binary modulation is being developed in which channel bits are arranged on a two-dimensional hexagonal lattice [W. M. J. Coene, in Optical Data Storage, Vol. 88 of OSA Trends in Optics and Photonics Series (Optical Society of America, Washington, D.C., 2003), pp. 90-92]. The aim is to increase the capacity by a factor of 2 and the data rate by a factor of 10 over third-generation Blu-ray Disc technology. Following a route similar to that used in one-dimensional conventional optical storage [Jpn. J. Appl. Phys. 42, 1074 (2003)] could lead to a further increase in capacity by the addition of another dimension to writing data, such as the use of multiple levels instead of the two levels (pit and land) used in the binary TwoDOS disk format. We present a nonlinear signal-processing model for signal waveform generation as a function of the M-ary channel symbols, as well as simulated signal readouts for multilevel TwoDOS. 相似文献
17.
High Speed Signal Wavelength Conversion Using Stimulated Raman Effect in Ultrasmall Silicon-on-Insulator Optical Waveguides
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We propose the high speed signal wavelength conversion based on stimulated Raman effect on silicon waveguides. Simulation results of non-return-to-zero (NRZ) pseudorandom bit sequence (2^7-1 code) at 500-Gb/s rate of conversion in an ultrasmall silicon-on-insulator (SOI) optical waveguide are presented by co-propagating pump optical field. The most attractive issue is that the inverted converted signal can be obtained at the same wavelength as that of primary signal. In addition, the conversion performances, including extinction ratio (ER) and average peak power of conversion signal, depend strongly on the launching pump intensity. 相似文献
18.
光盘信息符的横向尺寸决定了光存储系统的存储面密度。采用二维正方形光栅作为光盘模型,通过三维矢量衍射理论的数值仿真,计算了信息符横向尺寸对读出信号调制度的影响,确定了最佳调制度对应的最佳坑宽。并与标量衍射理论的定性分析进行了对比。根据标量衍射理论,最佳调制度应出现在信息符面积为读出光斑面积一半时对应的信息符尺寸附近,且小于该尺寸;信息符的最佳坑宽,即信息符特征宽度取决于所用的光学系统;矢量衍射理论的定量计算结果符合标量衍射理论的分析,并更接近实际情况;标量衍射理论概念简单,适于定性分析,定量计算则存在较大的误差。 相似文献
19.
A Group-Period Phase Comparison Method Based on Equivalent Phase Comparison Frequency 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Based on the principle of equivalent phase comparison frequency, we propose a group-period phase comparison method. This method can be used to reveal the inherent relations between periodic signals and the change laws of the phase difference. If these laws are applied in the processing of the mutual relations between frequency signals, phase comparison can be accomplished without frequency normalization. Experimental results show that the method can enhance the measurement resolution to 10-13/s in the time domain. 相似文献
20.
Ultra-Stable Rubidium-Stabilized External-Cavity Diode Laser Based on the Modulation Transfer Spectroscopy Technique
下载免费PDF全文
![点击此处可从《中国物理快报》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We construct an ultra-stable external-cavity diode laser via modulation transfer spectroscopy referencing on a hyperfine component of the ST Rb D2 lines at 780 nm. The Doppler-free dispersion-like modulation transfer signal is obtained with high signal-to-noise-ratio. The instability of the laser frequency is measured by beating with an optical frequency comb which is phase-locked to an ultra-stable oven controlled crystal oscillator. The Allan deviation is 3.9 × 10-13 at I s averaging time and 9.8 ×10-14 at 90s averaging time. 相似文献