共查询到17条相似文献,搜索用时 234 毫秒
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部分相干光被环形透镜聚焦而产生的焦移 总被引:2,自引:0,他引:2
从理论上研究部分相干光被一环形透镜聚焦,在焦点附近的轴上点的光强分布。研究结果表明,当部分相干光被一环形透镜聚焦时,最大聚焦光强不在几何焦点,而是位于透镜与几何焦点之间,出现焦移现象。并且,焦移量不仅依赖于透镜外半径的菲涅耳数,还依赖于部分相干光的空间相干度和中心拦截比。透镜的菲涅耳数越小,焦移越大;部分相干光的空间相干度越低,焦移越大。当菲涅耳数一定时,环形透镜的中心拦截比越大,焦移越大;当空间相干度很小时,情况就变得比较复杂。 相似文献
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部分相干光经柱面球差透镜聚焦所产生的焦移 总被引:7,自引:7,他引:0
利用Collins公式得出光强均匀部分相干光经柱面球差透镜聚焦后的轴上光强分布,并通过数值模拟的方法研究了入射光的菲涅耳数、相干度和透镜的球差对轴上点光强分布的影响.结果显示,当菲涅耳数较小、空间相干度较小的部分相干光经无球差透镜聚焦时,轴上点光强分布会产生焦移现象,而当部分相干光被球差透镜聚焦时,也会有焦移现象产生. 相似文献
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部分相干修正贝塞尔高斯光束通过球差透镜的聚焦特性 总被引:2,自引:2,他引:0
由部分相干光的传输理论出发,对部分相干修正贝塞尔高斯光束通过球差透镜聚焦后轴上光强分布进行了研究.数值计算表明:当光谱相干度较小时,正、负球差对应的最佳聚焦点位于无球差时对应的最佳聚焦点的两侧;当光谱相干度较大时,正、负球差对应的最佳聚焦点将位于无球差时对应的最佳聚焦点的左侧.研究进一步表明,最佳聚焦点随着透镜菲涅耳数的增大向几何焦点方向靠近,并趋于一个定值.当光束菲涅耳数为1时,无球差时对应的最佳聚焦点逐渐趋于0.908,该值与光谱相干度无关,当透镜具有球差时,该值与光谱相干度有关. 相似文献
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杨氏双缝干涉实验中光谱奇异现象的特性分析 总被引:1,自引:1,他引:1
研究了完全相干光和部分相干光分别照射双缝时,杨氏双缝干涉实验中干涉场区的光谱变化现象.根据干涉场中光谱标准矩定义了光谱的相对光谱移动和相对光谱增宽,并利用相对光谱位移和相对光谱增宽分析了光谱奇异现象的特性.研究结果表明,入射光的某些光谱参量(如源光谱宽度Γ0,中心拦截比ε,相对空间相干度Δ0)对相对光谱增宽的影响相当大.结果还表明了光谱标准矩方法是定量研究光在传输中的光谱变化以及光谱奇异现象的有效工具. 相似文献
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多色高斯-谢尔模型光束通过球差透镜的光谱变化 总被引:1,自引:1,他引:0
基于部分相干光的传输方程研究了多色高斯一谢尔模型光束通过球差透镜的光谱变化。结果表明,多色高斯一谢尔模型光束通过球羞透镜后的轴上光谱与空间相关参量β,球差系数C1,源光谱谱宽σ0,位置z有关。着重分析了球差对轴上光谱的影响,将所得的结果与无像差的理想情况作了比较。当无球差时,轴上光谱仅有蓝移,而有球差时,轴上光谱存在蓝移或红移,并会出现光谱分裂现象。在某些特定位置处,轴上光谱分裂为等高双峰,并有跃变出现。而且,球差对光谱的影响随空间相关性增加而变得明显。当空间相关参量减小到某一值时,光谱分裂消失。 相似文献
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从部分相干光的传输理论出发,研究了高斯-谢尔模型光束通过光阑像散透镜聚焦的光谱异变和光谱开关。研究表明,在考虑像散的情况下,聚焦场轴上也会出现光谱异变和光谱开关。光谱异变和光谱开关不仅与空间相关性、截断参量、菲涅耳数和源光谱谱宽有关,透镜像散对光谱异变和光谱开关也会产生影响。通过数值计算结果,重点对透镜像散对光谱移动和光谱开关的影响进行了分析。与无像散情况相比,像散会使出现光谱开关的临界位置发生变化,当像散较大时出现光谱开关的临界位置明显向几何焦面移动,特别是当像散增加到一定数值时,光谱开关会消失。 相似文献
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The spectral changes of a partially coherent polychromatic light focused by an apertured lens with chromatic aberration are investigated. It is demonstrated that the spectrum in the focused field is different from that in the aperture. Comparing with the spectrum in the aperture, the spectrum in the focused field shifts to lower or higher frequency, which is defined as a spectral shift. The influence of chromatic aberration of the lens, the coherence of the partially coherent light in the aperture, the radius of the aperture, and the spectral width of the spectrum of the aperture on the spectral shift are investigated in detail. The numerical results show that these parameters affect the spectral shift noticeably. 相似文献
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In this paper, the effects of chromatic aberration of a focusing lens on the normalized spectrum of the partially coherent light at the geometrical-image plane are investigated experimentally. The experimental results show that, compared to the source spectrum, the normalized spectrum of the partially coherent light at the geometrical-image plane shifts either towards the red side or towards the blue side, which is dependent on the position of the observation point. In particular, the normalized spectrum splits into two peaks at some points and the spectral switch occurs at the critical point. Furthermore, each of the two peaks of the normalized spectrum still split into two subpeaks respectively at some points and the spectral switch occurred in the short-wavelength range of the normalized spectrum is also observed at another critical point. 相似文献
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In this paper, we investigated both theoretically and experimentally the normalized spectrum of partially coherent light radiated from a secondary source which is produced by an imaging system. The experimental results show that, if the imaging lens is achromatic, the normalized spectrum of the light radiated from a secondary source shifts either towards the red side or towards the blue side, compared to the spectrum of the source, and the spectral shifts change for different position of the observation points. It is found that the experimental results are consistent with the theoretical ones. A chromatic lens, acting as the imaging lens, is used to investigate the effect of the chromatic aberration on the normalized spectrum of the light field. The results show that the influence of the chromatic aberration on the normalized spectrum is considerable and cannot be neglected in high-precision spectral measurement experiments. 相似文献
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Based on the beam model for the flattened multi-Gaussian beams (FMGBs) with an axial shadow and partially coherent theory, the expression for cross-spectral density of partially coherent FMGBs with an axial shadow has been given, and the analytical expression for the spectral intensity of partially coherent FMGBs with an axial shadow passing through paraxial ABCD optical systems has been derived. The spectral shift of partially coherent FMGBs with an axial shadow focused by a thin lens has been analyzed quantitatively. The effects of the beam profile, spatial coherence parameter and the system parameters on the relative spectral shift have been discussed in detail. Our results show that the spectral intensity and the spectral shift of partially coherent FMGBs with an axial shadow passing through paraxial ABCD optical systems depend on the source spectral density, the generalized Fresnel number of the system, the transverse coordinate, the spatially coherence parameter, as well as the beam orders. 相似文献
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Starting from the propagation law of partially coherent light, the focusing properties of twisted Gaussian Schell-model (TGSM) beams passing through an optical system consisting of an aperture lens or through a system consisting of a separated aperture and lens are studied. The propagation expressions for focused TGSM beams have been derived. Our main attention is focused on the effect of the coherence of partially coherent light, the twist parameter and the distance between the aperture and lens on the focusing properties of TGSM beams. Numerical calculation results are given to illustrate how the coherence of partially coherent light, the twist parameter and the distance between the aperture and lens affect the axial irradiance in the focused field. 相似文献
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基于部分相干光的传输理论,研究了部分相干平顶高斯光束通过球差透镜聚焦后轴上点的光强分布。数值计算表明:轴上最佳聚焦点随着球差从负到正的变化而向几何焦点方向移动;光束阶数越大,实现最佳聚焦点越过几何焦点所需的正球差值越小;正负球差对应的最佳聚焦点始终分居于无球差时最佳聚焦点的两侧;轴上最佳聚焦点的光强随着球差从负到正的变化而变小;当正负球差绝对值较大时,光强随球差的变化较为缓慢,而在球差值为0附近,光强随球差的变化比较剧烈。 相似文献