Ridge waveguide as a near field aperture for high density data storage
Ridge waveguide as a near field aperture for high density data storage
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DOI：
10.1063/1.1771477
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发表时间：
2004-09-01
影响因子：
3.2
通讯作者：
Peng, CB
中科院分区：
文献类型：
--
作者：
Sendur, K;Challener, W;Peng, CB
研究了脊形波导作为数据存储系统近场孔径的性能。数值模拟采用有限元法和时域有限差分法。为了验证其精度在光学频率，有限元法和FDTD分析结果进行了比较。这些技术在光学频率的脊形波导建模的准确性也进行了评估，通过比较他们的结果与彼此的平面波照明。有限元法，这是能够模拟聚焦光束，然后用来模拟各种几何形状，包括脊波导。脊波导换能器的近场辐射可用功率密度量表示。文献中的先前研究考虑换能器在自由空间中的性能，而不是在记录磁介质的存在下。采用数值模拟的方法讨论了记录磁介质对传输效率和光斑尺寸的影响。研究和讨论了各种几何参数对光斑尺寸和传输效率的影响。基于我们的数值模拟，一个有前途的换能器设计，建议获得强烈的光斑远低于衍射极限。数值模拟表明，可以获得记录磁介质中的31 nm的半峰全宽光斑直径。对于100 mW输入功率，记录介质中吸收光功率密度的最大值约为1.67 × 10（-4）mW/nm（3）。在轨道和跨轨道的配置文件，这种设计进行了比较与高斯分布。(C)2004年，美国物理学会。
The performance of the ridge waveguide as a near-field aperture in data storage systems is investigated. Finite element method (FEM) and finite-difference time-domain (FDTD) based software are used in the numerical simulations. To verify their accuracy at optical frequencies, the FEM and FDTD are first compared to analytical results. The accuracy of these techniques for modeling ridge waveguides at optical frequencies is also evaluated by comparing their results with each other for a plane wave illumination. The FEM, which is capable of modeling focused beams, is then used to simulate various geometries involving ridge waveguides. Near-field radiation from ridge waveguide transducer is expressed in terms of power density quantities. Previous studies in the literature consider the performance of the transducer in free space, rather than in the presence of a recording magnetic medium. The effect of the recording magnetic medium on the transmission efficiency and spot size is discussed using numerical simulations. The effect of various geometric parameters on the optical spot size and transmission efficiency is investigated and discussed. Based on our numerical simulations, a promising transducer design is suggested to obtain intense optical spots well below the diffraction limit. Numerical simulations suggest that a full width at half maximum spot diameter of 31 nm in the recording magnetic medium can be obtained. The maximum value of the absorbed optical power density in the recording medium is about 1.67x10(-4) mW/nm(3) for a 100 mW input power. In-track and cross-track profiles for this design are compared with Gaussian distributions. (C) 2004 American Institute of Physics.