共查询到20条相似文献,搜索用时 15 毫秒
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基于高斯聚焦激光束热效应的超分辨近场结构光盘存储(孔径型Super-RENS)中,应用光学特性导纳矩阵建立的盘片光传导模型,采用有限元分析软件FEMLAB对不同激光功率和脉宽下的Sb掩膜层的孔径形成情况进行数值仿真.结果表明,当一定脉宽的激光功率超过介质的阈值时,掩膜层将有超分辨孔径形成,且孔径大小随功率的增大而增大.理论分析与孔径型Super-RENS光盘样片在不同激光功率下进行写入的实验结果相符,说明光热效应可以较好地描述孔径型Super-RENS光盘掩膜层孔径形成的过程.
关键词:
光存储
孔径型
超分辨近场结构
光热效应 相似文献
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This paper reports the study of superresolution and extension of depth of focus (DOF) of three-zone binary phase filters (BPFs) under high numerical aperture (NA) focusing. Two three-zone BPFs (BPF1 and BPF2) are specially designed to achieve transverse superresolution and extension of DOF simultaneously for the optical disc system with an objective lens of NA = 0.65. Numerical simulations based on the vectorial diffraction theory indicate that the transverse focal spot size of this system can be as small as that of NA = 0.85 and its DOF is as large as that of NA = 0.6 with acceptable Strehl ratios (> 0.4 for BPF1 and > 0.35 for BPF2) and low side-lobe intensity ratios (< 10%) by using these BPFs. It suggests that the storage capacity of this optical storage system may be improved to the same as that of a system with an objective lens of NA = 0.85. Moreover, the strict requirement of the focusing servo system caused by decreasing wavelength or employing higher NA objective lens can be mitigated. Therefore, these BPFs presented in this paper should be highly interesting for applications of high density optical data storage. 相似文献
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Frank Przygodda Joachim Knittel Oliver Malki Heiko Trautner Hartmut Richter 《Optical Review》2009,16(6):583-586
Random phase masks in object and reference beam of page-based holographic storage systems suppress the DC-peak and improve
the overlap of both beams inside the storage material. Furthermore, they allow for a narrow shift-selectivity. In a holographic
setup the phase mask has to be introduced at a conjugate image plane of the spatial light modulator (SLM), if it is not fixed
directly on the SLM itself. A binary phase mask with cells generating 0 and π phase shifts has to be aligned very accurately
with respect to the SLM pixels, otherwise image artifacts disturb the received data page. We present a phase mask, where the
phase cells have the size of a data block which consists of a rectangular set of SLM pixels. Additionally, the corresponding
data page has no data at the position of phase jumps and thus relaxes the alignment tolerance significantly. 相似文献
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Calculations have been done for the modulation transfer function of a superresolution optical disk with a combination of optical
path filtering and saturable absorption techniques. The results reveal that optical path filtering alone can only equalize,
to a certain degree, the spatial frequency response of the opticaldisk system, but it can not attain any response beyond the
cutoff frequency. With an additional saturable absorption layer in-between the substrate and the information layer, it is
found that the optical response both under and beyond the cutoff frequency can be greatly improved. 相似文献
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Direct-write laser micromachining of diamond on a submicrometer scale with a near-field scanning optical microscope with an uncoated tapered fiber tip has been demonstrated. Micromachined structures can be imaged in situ immediately after modification of the sample. An early stage of the ablation process, which is believed to be conversion of diamond into graphite, has been visualized. 相似文献
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A three-dimensional optical data storage system that combines a new recording material with a microholographic data format in which data are stored as single-bit microholograms is presented. This format offers less sensitivity to environmental conditions than the page-based holographic approach in addition to an increased compatibility with current storage technologies. The new recording material is based on a thermoplastic material. The results presented indicate that the dimensions of the microholograms are larger than those calculated by use of simple laser beam waist approximations and that multiple layers of microholograms would significantly affect signal levels. Data densities achievable with the microholographic format will likely be limited by those effects. 相似文献
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《中国物理 B》2019,(10)
Recent years, optically controlled phase-change memory draws intensive attention owing to some advanced applications including integrated all-optical nonvolatile memory, in-memory computing, and neuromorphic computing. The light-induced phase transition is the key for this technology. Traditional understanding on the role of light is the heating effect. Generally, the RESET operation of phase-change memory is believed to be a melt-quenching-amorphization process. However, some recent experimental and theoretical investigations have revealed that ultrafast laser can manipulate the structures of phase-change materials by non-thermal effects and induces unconventional phase transitions including solid-to-solid amorphization and order-to-order phase transitions. Compared with the conventional thermal amorphization,these transitions have potential superiors such as faster speed, better endurance, and low power consumption. This article summarizes some recent progress of experimental observations and theoretical analyses on these unconventional phase transitions. The discussions mainly focus on the physical mechanism at atomic scale to provide guidance to control the phase transitions for optical storage. Outlook on some possible applications of the non-thermal phase transition is also presented to develop new types of devices. 相似文献
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A novel read-only super-resolution optical disc structure (substrate/mask layer/dielectric layer) is proposed in this paper. By using a Si thin film as the mask layer, the recording pits with a diameter 380nm and a depth 50nm are read out on the dynamic measuring equipment; the laser wavelength α is 632.8nm and the numerical aperture is 0.40. In the course of reproduction, the laser power is 5mW and the rotation velocity of the disc is 4m·s-1. The optimum thickness of the Si thin film is 18nm and the signal-to-noise ratio is 32dB. 相似文献
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Y.-F. Chau Y.-S. Sun D.P. Tsai T.-J. Yang 《Applied Physics A: Materials Science & Processing》2007,89(2):381-385
The deformation and plasmon effects of collective localized surface plasmons between incident light and bubble-pit AgOx-type super-RENS structure have been studied using finite-difference time-domain (FDTD) method. We find that the polarization,
wavelength of incident light, and particle sizes of Ag nanoparticles are sensitive to the plasma resonance. The Ag nanoparticles
inside the bubble-pit AgOx-type super-RENS structure give the additional outer boundaries to the motion of the Ag nanoparticles, and excite more evanescent
field which located in the far edge of the bubble from the optical axis of the incident beam. The optical properties between
active layer and incident light with polarization direction, different wavelengths, and varied particle sizes of Ag nanoparticles
exhibits nonlinear optical behavior in the near field. The far-field signals of different wavelength of incident light confirm
the relation between highly localized near-field distributions and enhanced resolution of far-field signals. The subwavelength
recording marks smaller than the diffraction limit were distinguishable since the Ag nanoparticles with high localized fields
transferred evanescent waves to detectable signals in the far field.
PACS 42.79.Vb; 71.15.Rn; 72.15.Rn; 73.22.-f; 73.22.Lp; 78.67.Bf; 73.20.Mf 相似文献
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Use of two-photon excitation for erasable-rewritable three-dimensional bit optical data storage in a photorefractive polymer 总被引:3,自引:0,他引:3
We report what is believed to be the first use of a photorefractive polymer in erasable-rewritable three-dimensional bit optical data storage under two-photon excitation. We successfully demonstrate writing, erasing, and rewriting of multilayered information in a photorefractive polymer consisting of 2,5-dimethyl-4-(p-nitrophenylazo)anisole, 2,4,7-trinitro-9-fluorenone, 9-ethylcarbazole, and poly(N-vinylcarbazole). A three-dimensional bit density of 5 Gbits/cm(3) is achieved by two-photon absorption under pulsed beam illumination at an infrared wavelength of 800 nm in the recording process. Complete erasing of the recording information is achieved by use of ultraviolet illumination. 相似文献
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Use of continuous-wave illumination for two-photon three-dimensional optical bit data storage in a photobleaching polymer 总被引:4,自引:0,他引:4
We show that a continuous-wave laser beam at an infrared wavelength of 800 nm can be used for two-photon three-dimensional bit data storage in a photobleaching polymer. We successfully demonstrate recording and reading of six layers of data bits with a transverse bit separation of 4.3microm and an axial layer separation of 20microm . This result leads to a three-dimensional bit density of approximately 3Gbits/cm(3) . 相似文献
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We determine a set of experimental parameters through the application of an evolutionary inversion procedure. The input to the algorithm is experimental apertureless scanning near-field optical microscope data. The performance of our inversion procedure is assessed by means of a comparison with a nonevolutionary technique. 相似文献
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光存储中的光学系统是一种非同轴光学系统,其中各个光学元件的设计位置与装配精度是保证系统光线正常传输并获得准确信号的前提。四元数方法是一种可以方便地描述空间光线的传输计算与坐标变换的数学方法。通过将四元数引入到光学头光学系统的建模中,使用四元数法表征非同轴光学系统的传输方式,并给出建立光学元件的设计、安装参数与聚焦光斑、读出光斑之间关系的流程图。据此模型对各个独立的研究对象进行分析的结果,对光存储中光学系统的设计与生产装配工艺的制定有指导意义;同时,以此模型分析物镜的连续运动对光斑和读出信号的影响,对光学头中的可执行机构力矩器的设计有实践作用。 相似文献