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关于康托集类光栅的实验探究 总被引:1,自引:1,他引:0
设计制作了康托集分形衍射光栅,通过对康托集分形光栅3个阶段的夫琅禾费衍射现象的观察,根据惠更斯-菲涅耳原理,得到了一维康托集分形光栅的夫琅禾费衍射光强分布特性. 相似文献
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衍射光栅它在当今信息时代是一种不可或缺光学元件,特别是在光谱学、激光工艺、光学信息处理、光通信等许多领域中都有着十分重要的应用。本文以康托集分形光栅为研究对象,自行设计并观察了康托集分形光栅三个阶段的夫琅和费衍射现象,根据惠更斯.菲涅耳原理,讨论了一维康托集分形光栅的夫琅和费衍射光强分布特性。 相似文献
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衍射光栅的傅里叶分析方法 总被引:3,自引:0,他引:3
本文用衍射理论中的傅里叶分析方法,分析光栅在各种不同情况下的夫琅和费衍射现象中,其衍射屏上的复振幅分布、光强分布及频谱分布的规律。对于衍射光栅的应用具有指导意义。 相似文献
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The phase diversity wavefront sensor is one of the tools used to estimate wavefront aberration, and it is often used as a wavefront sensor in adaptive optics systems. However, the performance of the traditional phase diversity wavefront sensor is limited by the accuracy and dynamic ranges of the intensity distribution at the focus and defocus positions of the CCD camera. In this paper, a modified phase diversity wavefront sensor based on a diffraction grating is proposed to improve the ability to measure the wavefront aberration with larger amplitude and higher spatial frequency. The basic principle and the optics construction of the proposed method are also described in detail. The noise propagation property of the proposed method is also analysed by using the numerical simulation method, and comparison between the diffraction grating phase diversity wavefront sensor and the traditional phase diversity wavefront sensor is also made. The simulation results show that the diffraction grating phase diversity wavefront sensor can obviously improve the ability to measure the wavefront aberration, especially the wavefront aberration with larger amplitude and higher spatial frequency. 相似文献
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Phase diversity wavefront sensor is one of the useful tools to estimate the wavefront aberration, and it is often used as a wavefront sensor in adaptive optics system. However, the performance of the traditional phase diversity wavefront sensor is limited by the accuracy and dynamic ranges of the intensity distribution at focus and defocus positions of the CCD camera. In this paper, a modified phase diversity wavefront sensor based on a diffraction grating is proposed to improve the ability to measure the wavefront aberration with larger amplitude and higher spatial frequency. The basic principle and the optics construction of the proposed method are also described in detail. The noise propagation property of the proposed method is also analysed by using the numerical simulation method, and comparison between the diffraction grating phase diversity wavefront sensor and the traditional phase diversity wavefront sensor is also made. The simulation results show that the diffraction grating phase diversity wavefront sensor can obviously improve the ability to measure the wavefront aberration, especially the wavefront aberration with larger amplitude and higher spatial frequency. 相似文献
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A newly designed grating used in terahertz region is proposed, which is composed of the trapezoidal elements repeated successively along one dimension of the substrate, and uniform interval(the grating period) repeated along the other dimension. The transmission of the grating owns a designable trapezoidal profile dependent on the geometric dimensions of the element. The far-field diffraction patterns of a designed grating at incident broadband terahertz frequencies, with element dimensions of upper, lower side and period of 50, 250, and 300 μm, respectively, are simulated by the scalar diffraction theory. The simulation results indicate that the terahertz grating exhibits a property of single-order diffraction,and the diffraction efficiency of the first order reaches 6.6%, exceeding that of a traditional sinusoidal amplitude grating with identical period and duty cycle. Owing to the regular architecture and the high single-order diffraction efficiency, the grating is easy to fabricate and shows great potential applications in single-shot spectral measurements of weak broadband terahertz pulse. 相似文献
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The Talbot effect in the diffraction of light on the amplitude diffraction grating has been investigated experimentally. A high-order fractional Talbot effect up to d/102, where d is the grating period, has been discovered and studied. Possible applications of this phenomenon have been mentioned. 相似文献
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The generation of amplitude and phase gratings in an absorbing medium is discussed, including the effects of light polarization, population kinetics and orientational relaxation. A theory is given which describes light diffraction by a combination of an amplitude and a phase grating. It is shown that the coherent coupling effect in transient absorption measurements is solely due to the amplitude grating. Weak absorption and a low triplet yield favour diffraction of the probing beam by the phase grating in triple-beam experiments. Phase grating experiments can be performed with highly soluble absorber dyes, the absorption maximum of which is far away from the laser wavelength. Due to photoselection, diffraction by an amplitude grating depends on the polarization of the probing beam while phase grating diffraction is insensitive to this. Perpendicular polarization of the two exciting pulses prevents the buildup of a phase grating and results in light diffracted by the amplitude grating that is proportional to the transient dichroism signal as known from the common absorption relaxation. 相似文献
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本文提供一种测量两束相干的ps光脉冲的空间二维时间振幅相关函数的新方法.在此方法中,光脉冲是被记录在一种光致折变的体积全息介质中,而所记录的信息可以通过直接量度在介质中所形成的光栅的空间分布而读出.这种方法可的可行性已为实验证实,它是通过3.5ps倍频锁模Nd:YAG激光测量光致折变晶体LiNbO3来实现的。 相似文献