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H.-E. Hwang 《Optical and Quantum Electronics》2003,35(15):1335-1350
The diffraction characteristics of a broad-band light source from a rectangular mask with a circular aperture array in the far field are theoretically investigated with a rapid and precise mathematical derivation. We provide a rigorous treatment of a time dependent Gaussian-shaped pulsed beam passing through a rectangular mask with a circular aperture array and give more accurate and concrete criteria judging the timing for the spectral red shift, blue shift, and splitting of light distributions as well. In addition, the distortion of the space-time diffraction intensity distribution is also presented in detail. This study shows the mathematically analytic form for a pulsed beam incident on an array of small apertures, when the usage of lenses is not practical. Also, the energy distribution of the pulse in the frequency domain is presented to benefit the understanding of its applications in optics information systems. 相似文献
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The spectrum change of a Gaussian pulse in the far field is studied with the Fresnel diffraction integral when it is incident on an aperture with Gaussian form transmittance. It is found that the side-lobes of the diffracted spectral intensity, which exist in a normal circular aperture with unit transmittance, can be eliminated completely under such a condition. Also, the red shift and blue shift of the spectral intensity maximum of the incident pulse are presented. 相似文献
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The diffraction spectral intensity characteristics of a time-dependent Gaussian pulse from an apodized circular aperture in the far field are studied both theoretically and numerically. It is shown that the apodization of the diffracted Gaussian pulse spectrum can be found. Also the red or blue shift of the spectral intensity maximum of the incident pulse is presented. 相似文献
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The diffraction characteristics of a broadband light source from a circular aperture in the near-field are clarified theoretically via prompt and precise mathematical derivation. This paper provides a explicit way of treating in the case of time dependent Gaussian-shaped pulsed beam passing through a circular aperture and gives more accurate and concrete criteria for judging the timing of the spectral red shift, blue shift and splitting of light distributions. Furthermore, the results offer an understanding of the Gaussian beam quality of the output of an optical resonator in the near-field. 相似文献
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提出将空间域的透镜列阵法和时间域的光谱色散平滑法结合起来实现靶面的均匀辐照. 消衍射型透镜列阵能获得边缘陡峭且顶部较平坦的准近场焦斑,光谱色散平滑则能有效地抹平焦斑内部由多光束干涉引起的细密条纹. 数值结果显示,通过该方案能获得均匀性较好的焦斑. 进一步分析了光谱色散平滑单元中位相调制和光栅的参数对辐照均匀性的影响,发现参数的选取要在焦斑均匀性和能量利用率之间取得合理平衡,以在整体上获得最佳的均匀辐照效果.
关键词:
光谱色散平滑
透镜列阵
衍射
多光束干涉 相似文献
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The spatial correlation properties and the spectral intensity distributions of focused Gaussian Schell-model (GSM) array beams are studied in detail. The closed-form expressions for the spectral degree of coherence and the spectral intensity of focused GSM array beams are derived. It is shown that the spectral degree of coherence of focused GSM array beams is the same as that of focused GSM beams in the focal plane. On the other hand, it is found that, in the focal plane the spectral intensity distribution of focused GSM array beams is the fringe pattern when the value of the coherence length is small. However, it becomes one peak located at the center as the value of the coherence length is large enough. In the focal plane, the spectral intensity maximum increases and the width of the normalized spectral intensity distribution decreases as the beam number increases. In general, for GSM array beams, the width of the modulus of the spectral degree of coherence in the focal plane always exceeds that of the normalized spectral intensity distribution, which is different from the behavior of focused GSM beams. In addition, the power in the bucket (PIB) and the beam propagation factor (M2 factor) are also discussed. The main results are explained physically. 相似文献