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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.
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   

3.
李明智  姜文 《光子学报》1992,21(2):186-192
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   

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   

5.
赵石磊  耿永友  施宏仁 《光学学报》2012,32(6):631004-310
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.
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   

7.
Metal organic vapour phase epitaxy (MOVPE) is nowadays one of the leading techniques for epitaxial growth. While the processes in the gas phase of MOVPE are reasonably well understood, the processes on the growing surface are not. This situation is in contrast to molecular beam epitaxy (MBE), where considerable knowledge about growth processes on the surface could be gained. The main reason is that all the UHV-based classical surface-science tools (using electrons and ions), especially reflection high-energy electron diffraction, can be applied in the vacuum-based MBE but not under the gas-phase conditions of MOVPE. This situation has changed in the last decade since optical surface-science tools have been developed. Especially, with the linear optical techniques like reflectance anisotropy spectroscopy and spectroscopic ellipsometry, there is now a quasi-standard tool at hand which allows for the study of all kinds of pregrowth and growth situations in MOVPE (in MBE of course, as well). These optical methods give, moreover, chemical information also. In this article we will describe shortly the features of these optical techniques and then concentrate on III-V-semiconductor growth. The spectral definition of surface reconstructions and time-resolved studies of phase transitions between them (adsorption/desorption kinetics of group-III and group-V elements) are discussed next. Under growth, the surfaces can be classified and defined according to their optical surface response into a pressure versus temperature phase diagram. The regions of such a phase diagram correspond to different geometrical and chemical surface structures and consequently lead to different growth modes. Finally, as an example of modern nanogrowth, monitoring of the growth of quantum-dot structures is presented. Received: 2 August 2001 / Accepted: 23 October 2001 / Published online: 3 April 2002  相似文献   

8.
Preface     
Saito  Kimihiro 《Optical Review》2021,28(6):673-680
Optical Review - To increase the recording density of optical discs, analog recording techniques such as the use of orthogonal frequency division multiplexing (OFDM) method has been investigated....  相似文献   

9.
Dispersive phenomena provide limits in the generation, measurement and applications of femtosecond optical pulses. Optical elements such as prisms, gratings, air, mirrors, filters, and laser crystals all contribute to the total dispersion in optical systems. Interferometric techniques enable measurements of dispersion of individual elements, and new techniques allow dispersion measurement inside the cavity of operating modelocked femtosecond tunable lasers. These techniques provide access to detailed information about dispersion errors which can distort pulses and produce undesirable effects in modelocked lasers. In this article, we review techniques for the measurement of dispersion in optical components and systems. In several cases, we compare measurements made with intracavity dispersion techniques with extracavity measurements and point out common features.  相似文献   

10.
This paper provides the analysis of wavelength converted pulses obtained with a simple semiconductor optical amplifier (SOA)-based wavelength conversion scheme, which exploits cross phase modulation (XPM) in an SOA in conjunction with shifted filtering. The analysis includes experimental measurements of the back-to-back system performances as well as frequency-resolved optical gating (FROG) characterisations of the wavelength converted pulses. These measurements are implemented at different bit rates up to 80 Gbit/s and for both red and blue-shifted filtering, particularly showing different patterning effect dependencies of red and blue-shifting techniques. This analysis is developed by the addition of a numerical study which corroborates the experimental results. A further understanding of the different performances of red and blue filtering techniques, presented in the literature, can thus be proposed. The placement of the filter to undertake red-shifted filtering (RSF) allows us to achieve very short pulse widths but high bit rate operation is limited by pattern effects. The blue-shifted filtering (BSF) technique shows optimum performance as regards to patterning effects even if the wavelength converted pulses can be larger.  相似文献   

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