散射中心型超分辨近场结构的非线性光学特性研究进展

超分辨近场结构(Super-RENS)技术是近年来发展起来的一种新型近场光存储技术，是目前最有实用化前景的纳米尺度近场超分辨技术之一。初步研究表明，其近场超分辨特性与非线性响应密切相关，研究其非线性光学特性对阐明物理机制、发展新的掩模材料和非线性光学应用都具有重要意义。对散射中心型超分辨近场结构非线性光学特性的最新研究进展进行了介绍和分析。

Dynamic readout of subdiffraction-limited pit arrays with a silver superlens

Recent theoretical and experimental results suggested that the silver superlens could be constructed through controlling silver thin film thickness and preparation conditions, and applied in subdiffraction-limited optical imaging and optical lithography. In this work, we report another significant application of silver superlens-ultrahigh density optical data storage. With the silver superlens the subdiffraction-limited pit arrays on an optical disk are dynamically read out and the carrier-to-noise ratio can reach 25 dB for the thin film thickness of 46 nm. The readout laser power and readout velocity have little effect on the carrier-to-noise ratio. Additionally, in our experiment the silver thin film thickness needs to be controlled in the range from 20 to 80 nm.

Optical transmission larger than 1 (T > 1) through ZnS-SiO2/AgOx/ZnS-SiO2 sandwiched thin films

Optical transmission through flat media should be smaller than 1. However, we have observed optical transmission up to T=1.18. The samples were ZnS-SiO2/AgOx/ZnS-SiO2 sandwiched thin films on glass substrate. The supertransmission could only be observed in the near field. We attribute the supertransmission to the lateral propagation relayed by the laser activated and decomposed Ag nanoparticles. (c) 2006 American Institute of Physics.

Rigorous transmittance analysis of a sub-wavelength Sb thin film lens

We quantitatively analysed the factors contributing to the optical transmission enhancement of a sub-wavelength Sb thin film lens, using the finite-difference time-domain (FDTD) method. The results show that the transmission enhancement of the dielectric with a Gaussian distributed refractive index loaded in a sub-wavelength circular hole is not only due to the high refractive index dielectric, but also due to the specific distributions of refractive index. It is the first study about the effects of the refractive index distribution on the transmission of a sub-wavelength aperture. This kind of lens has practical applications in the very small aperture lasers and for near-field optical storage and lithography.

Read-only memory disk with AgOx and AgInSbTe superresolution mask layer

Two novel read-only memory (ROM) disks, one with an AgOx mask layer and the other with an AgInSbTe mask layer, are proposed and studied. The AgOx and the AgInSbTe films sputtered on the premastered substrates with pit depths of 50 nm and pit lengths (space) of 380 nm are studied by atomic force microscopy. Disk readout measurement is carried out using a dynamic setup with a laser wavelength of 632.8 nm and an object lens numerical aperture (NA) of 0.40. Results show that the superresolution effect happens only at a suitable oxygen flow ratio for the AgOx ROM disk. The best superresolution readout effect is achieved at an oxygen flow ratio of 0.5 with the smoothest film surface. Compared with the AgOx ROM disk, the AgInSbTe ROM disk has a much smoother film surface and better superresolution effect. A carrier-to-noise ratio (CNR) of above 40 dB can be obtained at an appropriate readout power and readout velocity. The readout CNR of both the AgOx and AgInSbTe ROM disks have a nonlinear dependence on the readout power. The superresolution readout mechanisms for these ROM disks are analyzed and compared as well. (c) 2005 Society of Photo-Optical Instrumentation Engineers.

Synthesis, optical and thermal characterization of novel thiazolyl heterocyclic azo dye

Thiazolyl heterocyclic azo dye and its metal (Ni2+, Co2+)-azo complexes were synthesized. Their structures were confirmed by elemental analysis, UV-VIS absorption spectra, FT-IR, H-1 NMR and MALDI-MS. The thermal properties of metal complexes were studied by DSC-TGA. The optical constants (complex refractive index N=n + ik) and thickness of the complex thin films on polished single-crystal silicon substrates were investigated on a scanning ellipsometer. Results indicate that thiazolyl metal-azo complexes possess good optical and thermal properties. They would be a promising recording medium candidate for NVD with the Super-resolution near field structure (Super-RENS) technology. (c) 2007 Elsevier B.V. All rights reserved.

2-氨基-6-乙氧基苯并噻唑类偶氮染料及其金属鏊合物的合成及光学热学性能研究

合成了2-（2-氨基-6-乙氧基苯并噻唑基偶氮）-5-（N,N-二乙基氨基）三氟甲基磺酰苯胺偶氮染料（EBTDATFS）及其与乙酸镍、乙酸钴、乙酸铜、乙酸锌等金属盐鏊合的金属鏊合物。通过红外光谱、紫外-可见吸收光谱和MALDI质谱等对染料及其金属鏊合物进行了结构表征;使用旋涂方法在K9玻璃和抛光的单晶硅基片上制备薄膜;研究了镍金属鏊合物的热学性能;使用椭偏仪研究了Ni和Zn鏊合物的光学常数。结果表明：4种金属鏊合物薄膜最大吸收光谱为621-629nm,且长波边吸收峰陡峭;TGA-DSC测试结果表明镍金属鏊

纳米光存储薄膜结构的光学性质

近场超分辨纳米薄膜结构可以突破衍射极限实现纳米尺寸信息存储,是下一代海量存储技术的重要方案之一,也是纳米光子学研究中的热点。纳米膜层结构基于激光作用下的非线性局域光学效应实现超分辨。分析了超分辨近场薄膜结构突破衍射极限的光学原理,对超分辨纳米薄膜结构的表面等离子体激发特性、非线性光学特性、近场光学特性和超透镜效应等重要光学性质的最新研究进展做了系统介绍。

超分辨近场功能薄膜的膜层结构及其机理研究进展

超分辨近场结构光盘是最有希望达到100 GB以上的存储容量方式之一,而其记录和读出机理是研究中的重点,在近年文献研究的基础上,阐述了超分辨近场功能薄膜的膜层结构及其机理的研究进展。

超分辨近场结构中二元共晶合金掩膜的工作机制

超分辨近场结构(super-RENS)技术通过在传统光盘结构中插入掩膜结构而实现近场超分辨,是目前最具实用化前景的超高密度光存储技术之一,其中掩膜层的近场光学特性是决定其光存储性能的关键。利用三维时域有限差分法(3D-FDTD)对合金掩膜的近场光强分布进行了数值仿真和分析,提出二元共晶合金薄膜在激光作用下形成的规则微结构可能是以其作为掩膜层的超分辨近场结构光盘产生较高信噪比(SNR)的原因。

静动结合的化学腐蚀法制备近场光学探针的理论分析

理论上分析了静动结合的化学腐蚀法制备探针的具体机理及过程。在静态腐蚀的过程中, 利用流体力学Young-Laplace方程的一级近似解获得了光纤插入到HF酸中形成的新月形高度。在动态腐蚀过程中, 详细分析了当静态腐蚀时间和动态腐蚀时间分别取不同值时, 光纤移动速度对光纤探针结构的影响。利用此法可制备出尖端锐利、大锥角或多锥体等各种结构的光纤探针。这为实验上制备出性能优良的探针, 为拓宽扫描近场光学显微镜的应用范围奠定基础。将上述理论分析的结果与本文实验中所得初步结果进行了比较, 所得结果一致。

超分辨近场结构中Bubble微结构的远场光学特性分析

以菲涅尔-基尔霍夫衍射理论为基础,建立了超分辨近场结构中Bubble微结构对高斯光束的衍射模型.分析了PtOx型超分辨近场结构（PtOx-Type-Super-RENS）中Bubble微结构的远场光学特性.结果表明,设计的Bubble微结构形成过程的简化模型可基本反映超分辨近场结构中掩膜结构在激光作用下的结构变化过程,说明了高斯衍射模型是研究薄膜微结构变化的一种有效方法.

Structure and properties of amorphous thin film for optical data storage

In this paper the magnetic and magneto-optical properties of amorphous rare earth-transition metal (RE-TM) alloys as well as the magnetic coupling in the multi-layer thin films for high density optical data storage are presented. Using magnetic effect in scanning tunneling microscopy the clusters structure of amorphous RE-TM thin films has been observed and the perpendicular magnetic anisotropy in amorphous RE-TM thin films has been interpreted. Experimental results of quick phase transformation under short pulse laser irradiation of amorphous semiconductor and metallic alloy thin films for phase change optical recording are reported. A step-by-step phase transformation process through metastable states has been observed. The waveform of crystallization propagation in micro-size spot during laser recording in amorphous semiconductor thin films is characterized and quick recording and erasing mechanism for optical data storage with high performance are discussed. The nonlinear optical effects in amorphous alloy thin films have been studied. By photo-thermal effect or third order optical nonlinearity, the optical self-focusing is observed in amorphous mask thin films. The application of amorphous thin films with super-resolution near field structure for high-density optical data storage is performed. (c) 2007 Elsevier B.V. All rights reserved.

数值模拟探针诱导表面等离子体共振耦合纳米光刻

采用有损耗介质和色散介质的二维时域有限差分方法,数值模拟了以光波长514.5 nm的p偏振基模高斯光束为入射光源,激发Kretschmann型表面等离子体共振,并通过探针的局域场增强效应实现纳米光刻的新方法——探针诱导表面等离子体共振耦合纳米光刻.分别就探针与记录层的间距以及探针针尖大小,模拟分析了不同情况下探针的局域场增强效应和记录层表面的相对电场强度振幅分布.结果表明,探针工作在接触模式时,探针的局域场增强效应最明显,记录层表面的相对电场强度振幅的对比度最大;当探针针尖距记录层5 nm时,针尖下方记录层表面的相对电场强度振幅大于光刻临界值的分布宽度与针尖尺寸相近.

Study on readout durability of super-RENS disk

Characteristics essential for the readout durability of a superresolution near-field structure (super-RENS) disk are studied experimentally by using a home-built optical measuring setup and atomic force microscope, based on a simplified PtOx super-RENS disk. The experimental results show that for a super-RENS disk with constant structure and materials, readout signals including transmittance and reflectance vary with changes in bubble shape and size, indicating that the readout durability of the disk has a strong dependence on bubble stability, which is closely related to the thickness of the cover layer, the recording power and readout power, and the mechanical properties of the dielectric layer. Based on our experimental results, the main direction for improving readout durability is also proposed. (c) 2008 Optical Society of America.