首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   21篇
  免费   20篇
物理学   41篇
  2024年   1篇
  2020年   1篇
  2013年   1篇
  2012年   2篇
  2011年   1篇
  2010年   2篇
  2009年   4篇
  2008年   5篇
  2007年   6篇
  2006年   7篇
  2005年   4篇
  2004年   4篇
  1996年   2篇
  1995年   1篇
排序方式: 共有41条查询结果,搜索用时 31 毫秒
1.
Zhiguo Zhao  Kailiang Duan  Baida Lü 《Optik》2006,117(6):253-258
Based on the vectorial Rayleigh–Sommerfeld diffraction integrals, analytical expressions for the transversal and axial field distribution of plane waves propagating through a thin lens followed by a small circular aperture are derived and used to study the focusing and diffraction properties of plane waves. Some special cases of our general result are discussed, and illustrative numerical calculation results are given. It is found that the vectorial nonparaxial approach should be applied if the aperture dimension is comparable with the wavelength or the focusing is strong.  相似文献   
2.
Baida Lü  Pusheng Liu 《Optik》2004,115(5):223-226
Starting from the vectorial Rayleigh diffraction integral formula and using a simple expansion of the nucleus in the Rayleigh formula, an analytical propagation equation of vectorial nonparaxial Gaussian beams in free space is derived, which permits us to perform numerical calculations in comparison with the expression derived by Ciattoni et al. and with the direct numerical integration of the Rayleigh formula. It is found that as usual the use of expansion of vectorial Rayleigh diffraction integral is sufficient to provide satisfactory numerical results as compared with the direct integration of the Rayleigh formula. The above two analytical expressions are valid under certain conditions, however both are applicable in the far field.  相似文献   
3.
非傍轴光束的光束质量因子.I特性分析   总被引:3,自引:0,他引:3  
曹清  邓锡铭 《光学学报》1996,16(10):1345-1349
使用傅里叶变换和施瓦兹不等式证明:非傍轴标量光束的M2因子存在有一个只能无限趋近、却永远都不可能达到的下限1;并对一些与此相关的问题进行了讨论  相似文献   
4.
黎昌金  吕百达 《物理学报》2009,58(9):6192-6201
推导出二维非傍轴部分相干厄米-高斯(H-G)光束相干合成和非相干合成的交叉谱密度和光强的解析公式,并分析了一些特例. 合成光束的光强不仅决定于f参数,fσ参数,离轴参数,合成光束的束数和阶数以及传输距离z,而且还决定于合成方式. 对部分相干光的相干合成和非相干合成概念做了物理诠释,其正确性为数值计算例证实. 关键词: 部分相干光的相干和非相干合成 非傍轴部分相干厄米-高斯(H-G)光束 自由空间中的传输方程  相似文献   
5.
王红成  朱德海  凌东雄 《中国物理 B》2010,19(8):84207-084207
<正>The existence of one-dimensional bright Kerr solitons is investigated in Kerr media beyond the paraxial approximation. It is found that a nonparaxial soliton with no less than a minimum dimensionless width of about 0.76 can exist, which corresponds to the real width about a wavelength.Besides,the coherent interactions between two nonparaxial bright solitons in Kerr media are also investigated in detail.It is found that their separation and intensity ratio have great influence on the coherent interaction between these two solitons.Furthermore,the effect of the relative phase difference on the nonparaxial interaction is quite different from that on the paraxial interaction.Periodical breath, merging,repulsion,and energy transferring can be realized separately by choosing an appropriate initial relative phase between the coherent solitons.  相似文献   
6.
高曾辉  吕百达 《中国物理》2006,15(2):334-339
The concept of partially coherent nonparaxial modified Bessel--Gauss (MBG) beams is proposed. Based on the generalized Rayleigh-Sommerfeld diffraction integral, the analytical propagation equations of nonparaxial MBG beams in free space are derived and analysed, and some special cases are discussed. In particular, under the paraxial approximation our results reduce to the corresponding paraxial ones. Numerical calculation examples are given to illustrate the dependence of intensity and spectral degree of coherence on the beam order $m$, \textit{$\xi $} and $f$ parameters, and to compare the difference between the paraxial and nonparaxial results.  相似文献   
7.
Kailiang Duan  Baida Lü   《Optik》2004,115(5):218-222
Based on the vectorial Rayleigh diffraction integrals, a nonparaxial propagation equation of vectorial plane waves diffracted at a circular aperture is derived. The nonparaxial far-field expression, Fresnel and Fraunhofer diffraction formulae are given and treated as special cases of our general expression. The theoretical formulation permits us to study and compare the transversal and axial intensity distributions of diffracted plane waves both analytically and numerically. Illustrative numerical examples are given. It is shown that the vectorial nonparaxial approach has to be used if the aperture size is comparable with or less than the wavelength, and the knowledge of both transversal and axial intensity distributions is required to provide a comprehensive comparison of the paraxial and nonparaxial results.  相似文献   
8.
矢量非傍轴离轴高斯光束的传输   总被引:1,自引:0,他引:1       下载免费PDF全文
高曾辉  吕百达 《物理学报》2005,54(11):5144-5148
基于矢量瑞利-索末菲衍射积分公式,得出了波动方程的一个解,它代表矢量非傍轴离轴高斯光束,其在自由空间的传输方程表示为解析的结果.矢量非傍轴离轴高斯光束的轴上和远场公式,矢量非傍轴高斯光束的传输方程,以及傍轴的结果都可作为一般表达式的特例而得出.研究表明,f参数对光束的非傍轴特性有重要影响,而离心参数也影响非傍轴行为.与共轴情况不同的是,对离轴情况,在y方向存在场的纵向分量. 关键词: 激光光学 矢量非傍轴离轴高斯光束 瑞利-索末菲衍射积分 f参数 离轴参数  相似文献   
9.
In this study, we report on the fractional Talbot effect of nonparaxial self-accelerating beams in a multilevel electromagnetically induced transparency (EIT) atomic configuration, which, to the best of our knowledge, is the first study on this subject. The Talbot effect originates from superposed eigenmodes of the Helmholtz equation and forms in the EIT window in the presence of both linear and cubic susceptibilities. The Talbot effect can be realized by appropriately selecting the coefficients of the beam components. Our results indicate that the larger the radial difference between beam components, the stronger the interference between them, the smaller the Talbot angle is. The results of this study can be useful when studying optical imaging, optical measurements, and optical computing.  相似文献   
10.
The art of light engineering unveils a world of possibilities through the meticulous manipulation of photonic properties such as intensity, phase, and polarization. Precision control over these properties finds application in a variety of fields spanning communications, light–matter interactions, laser direct writing, and imaging. Terahertz (THz) range, nestled between microwaves and infrared light, stands out for its remarkable ability to propagate with minimal losses in numerous dielectric materials and compounds, making THz imaging a powerful tool for noninvasive control and inspection. In this study, a rational framework for the design and optimal assembly of nonparaxial THz imaging systems is established. The research is centered on lensless photonic systems composed solely of high-resistivity silicon-based nonparaxial elements such as the Fresnel zone plate, the Fibonacci lens, the Bessel axicon, and the Airy zone plate, all fabricated using laser ablation technology. Through a comprehensive examination through illumination engineering and scattered light collection from raster-scanned samples in a single-pixel detector scheme, the imaging systems are evaluated via diverse metrics including contrast, resolution, depth of field, and focus. These findings chart an exciting course toward the development of compact and user-friendly THz imaging systems where sensors and optical elements seamlessly integrate into a single chip.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号