【作者】 贺锋涛；

【导师】 侯洵；

【作者基本信息】 中国科学院研究生院（西安光学精密机械研究所） ， 光学， 2004， 博士

【摘要】 目前光存储技术在信息社会中发挥出越来越重要的作用，随着信息技术的发展，急需开发出具有更高存储密度的存储系统。本课题主要围绕高密度光存储技术中的短波长光存储技术和固体浸没透镜超分辨存储技术展开研究，其目的在于掌握这两种高密度光存储系统中的关键技术。 本文首先概述了高密度光存储技术的发展历史及现状。随后采用532nm绿光激光器，数值孔径0.65的非球面树脂物镜，建立了一套绿光存储实验装置。在建立装置中解决了亚微米尺寸激光光斑的聚焦、光盘离焦量检测及自动聚焦等问题，最终采用该装置在CD-RW相变光盘上进行了存储实验，实现了线宽约为500nm的记录线。且利用旋涂法制备了三甲川菁染料掺杂高分子薄膜，室温下采用该装置对三甲川菁染料薄膜的光存储特性进行了研究，得到了记录线宽约600nm的结果。以上结果的取得表明所建立的绿光存储实验装置已具备基本的存储实验功能。目前国内关于此方面的研究大多以综述为主，而该研究是建立在实验基础之上。 在固体浸没透镜（SIL）近场光存储方面，首先建立了适合SIL存储的初级光学系统，采用该系统与SIL相结合，建立了SIL静态存储装置，且在CD-RW相变光盘上，实现了线宽约为450nm的静态实验结果。该结果与非SIL存储系统的记录线宽相比，线宽压缩了1.44倍；同时利用电容位移检测原理，设计并完成了一种简单有效的SIL飞行头飞行高度检测装置，设计了高度伺服控制系统，最终实现了SIL在距离盘片几百纳米近场区域的高度检测与控制，目前国内相关文献尚未见这方面的报道。 在SIL飞秒三维光存储方面，首次提出将SIL用于飞秒激光三维光存储的方案，模拟了SIL离焦量与实际聚焦在介质内焦点位置及系统数值孔径大小的关系。且采用数值孔径0.55聚焦透镜与SIL相结合，将800nm、150fs钛宝石激光脉冲聚焦到存储介质内，在PMMA及石英介质内部实现了三维存储。其中，在石英介质内部存储密度可达1.1×10¹²bits/cm³，该结果为目前所报道在透明介质内所获得的最高存储密度。此外，本文还采用三维时域有限差分法，对聚焦线偏振高斯光束通过固体浸没透镜后焦平面上各分量场分布及距离焦平面不同位置光斑图样进行了模拟，模拟结果表明:在焦平面上及距离焦平面较近的近场区域，出射光场在与入射光偏振垂直方向出现显著的场增强现象，光斑图样呈近似椭圆分布;而在距焦平面较远的远场区域光斑图样趋向圆形对称分布。模拟结果对SIL用于近场光存储具有一定的理论指导意义。关键词:光存储，光盘，离焦检测，三维存储，自动聚焦，固体浸没透镜，高度检测，高度控制，飞秒激光脉冲，石英，近场，时域有限差分法。更多还原

【Abstract】 The technology of optical data storage is playing a more and more important role in our information society. It is necessary to imploit higher-density optical memory system with the development of data storage technologies. The high-density optical data storage technologies based on short-wavelength laser source and solid immersion lens are studied with the aim to develop the key technologies of the two optical data storages system.In this thesis, the history and the recent advances of high-density optical data storage are summarized firstly. Then, an experimental setup of optical storage system is built up, using a non-sphere colophony object lens with NA=0.65 and green light source with wavelength of 532nm. The system can focus the light beam in sub-micron meter scale, detect the focusing distance error and control the object lens to move to realize automatically focusing. Using phase-changing disc CD-RW as optical storage media, an optical storage experiment carries out with the system and the results shows that a recording track with the width of ~ 500nm is obtained. A Penta Methyl Crynine dye polymer film is made by spin- coated method, and the property of the film is studied with the system at room temperature. Finally a result of about 600nm recording line width on the film is obtained. The above results show that the basic optical writing function is provided with this optical storage system of green light source. At present most research about this are summarized within our country while our works are based on experiment.Using Solid Immersion Lens (SIL) is another method to realize near-field optical data storage. Here with a basic optical system of SIL, a static SIL optical storage system is built up, and a result of ~450nm recording track is obtained on CD-RW disc. Compared with the same system without SIL, the width ratio of recording track is1:1.44. Also a device that can control SIL to fly at a certain height to the surface of recording media is designed. The flying height of SIL is measured by the capacity between the SIL and the disc, and a computer controls the disc to accelerate or decelerate, to adjust the flying height of the SIL. And then, the SIL flying height can be controlled. The related works have not been reported within our country till now.A project that using the solid immersion lens to focus the femtosecond laser pulses in three-dimensional optical data storage is first proposed. The relationship between the actual focusing position and the numerical aperture with the distance of defocusing is calculated. Three-dimensional optical data storage is achieved in PMMA and fused silica by combining 800nm, 150fs laser pulses with NA=0.55 objective lens and solid immersion lens. A theoretical high-density storage as 1.1 x 10 bits/cm in fused silica is achieved. Such result is the highest writing density in transparent materials that is reported at present time.Besides, three component optical fields intensity of focused linear polarized gauss beam in the focal plane and the intensity patterns in the sections of various distance from the focal plane are simulated using three-dimensional finite-difference time-domain (FDTD) method. The results show that the image pattern in the focal plane or the sections near the focal takes on approximate ellipse, while the patterns in the planes of far region displays asymmetrical round. It may be possible to have some theoretical directing in solid immersion lens near-field data storage.更多还原