共查询到20条相似文献,搜索用时 140 毫秒
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为分析透镜系统中圆孔光栏和透镜失调对高斯光束聚焦特性的影响,利用椭圆光栏近似展开式和失调光学系统的广义衍射公式,推导高斯光束经含圆孔光栏失调透镜系统传输的近似解析式,得到输出光束光强极大值场分布与光束参量、孔径尺寸、光栏和透镜失调量之间的关系。针对特定透镜系统,定量分析失调量对输出光束聚焦特性的影响。结果表明:各元件的失调对输出光束聚焦特性均产生影响,在失调量较小时透镜横位移对输出光束聚焦特性的影响比透镜角位移对输出光束聚焦特性的影响更明显。 相似文献
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椭圆平顶高斯光束的聚焦特性 总被引:4,自引:4,他引:0
利用级数分解法把椭圆平顶高斯光束(EFGB)分解成多个椭圆厄密-高斯模的叠加形式,利用椭圆厄密-高斯模的传输公式导出了EFGB通过非轴对称光学系统的传输公式,该公式和直接用矢量积分得出的结果是等效的.利用导出的公式,我们计算分析了EFGB通过轴对称透镜和非轴对称透镜的聚焦特性.结果表明,EFGB聚焦后,近场光强分布变化很快,特别是焦点前后,光强分布会快速旋转.另外,EFGB的聚焦特性与阶次有关. 相似文献
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当高功率激光通过Kerr非线性介质传输时,Kerr效应会严重影响激光的传输特性.实际应用中常遇到像散光束.迄今为止,像散光束传输特性的研究大都局限于在线性介质中的传输,而在非线性介质中传输的研究较少,且还未涉及像散激光束通过含光学系统的Kerr非线性介质传输变换的研究.本文主要研究Kerr效应对聚焦光束像散特性和焦移特性的影响,以及聚焦像散高斯光束的自聚焦焦距和光束焦点调控.在光束扩展情况下,推导出了聚焦像散高斯光束在Kerr非线性介质中传输的束宽、束腰位置和焦移的解析公式,研究表明:在自聚焦介质中,随着自聚焦作用增强(如光束功率增强),光束像散越强,但焦移越小;在自散焦介质中,随着自散焦作用增强(如光束功率增强),光束像散越弱,但焦移越大.另一方面,在光束自聚焦情况下,推导出了自聚焦焦距的解析公式,研究表明利用光束像散可以调控光束焦点个数. 相似文献
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根据初级像差理论广泛研究了由左手性介质构造的平板透镜系统的赛德尔像差特性.由初级像差加和定理推导了适合于这种系统的赛德尔和数公式,并指出了寻找消赛德尔像差的平板透镜系统的方法.作为两个特例,分别讨论了消赛德尔像差的左手性介质单透镜和双胶合透镜系统. 相似文献
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ABCD matrix formalism for propagation of Gaussian beam through left-handed material slab system 总被引:2,自引:0,他引:2
We apply a simple ABCD matrix formalism to investigate beam propagation in left-handed material (LHM) slab systems. Firstly, we derive the expressions for the matrix elements for a single LHM slab. Based on the ABCD matrix, we obtain the field distributions both inside and outside the LHM slab, and the conditions for focusing and phase compensation of the Gaussian beam. Secondly, the derived ABCD law is applied to analyze the propagation properties of Gaussian beams through various cascaded LHM slab systems. The corresponding focusing and phase compensation conditions of the Gaussian beam are also obtained. Our theoretic formalism may be applied as a compact and effective tool for the research of light beam propagation in complex LHM slab systems, since it avoids the complicated integral operation. 相似文献
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On the basis of angular spectrum representation, a formalism describing paraxial beams propagating through an isotropic left-handed material (LHM) slab is presented. The treatment allows us to introduce the ideas of beam focusing and phase compensation by LHM slab. Because of the negative refractive index of LHM slab, the inverse Gouy phase shift and the negative Rayleigh length of paraxial Gaussian beam are proposed. It is shown that the phase difference caused by the Gouy phase shift in right-handed material (RHM) can be compensated by that caused by the inverse Gouy phase shift in LHM. If certain matching conditions are satisfied, the intensity and phase distributions at object plane can be completely reconstructed at the image plane. 相似文献
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《中国物理 B》2015,(4)
In this paper the propagation of elegant Hermite-cosh-Gaussian, elegant Laguerre Gaussian, and Bessel Gaussian beams through a Kerr left-handed metamaterial(LHM) slab have been studied. A split-step Fourier method is used to investigate the propagation of laser beams through this media. Numerical simulation shows that Gaussian beams have different focusing behaviors in a Kerr LHM slab with positive or negative nonlinearity. Beam focusing happens in slabs with positive nonlinearity and not in slabs with negative nonlinearity; however, negative nonlinearity is required for a Kerr LHM slab to act like a lens. Additionally, the focusing properties of beams can be controlled by controlling the thickness of the slab or the input power of the incident beam. A multilayer structure is also proposed to have beam focusing by thinner slabs and passing longer distances. 相似文献
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Based on the Rayleigh diffraction integral and complex analytical signal representation, the strict propagation expression and its Fourier spectrum for ultrashort pulsed Gaussian beams with constant waist width are derived, which have the general applicable advantage, because the paraxial approximation, pulsed envelope representation and far-field approximation are not invoked. The far-field and paraxial expressions are obtained as the special cases of our general results. Numerical calculation results are given to illustrate the spatiotemporal propagation properties of few- and single-cycle pulsed Gaussian beams with constant waist width. A comparison with the paraxial results and previous work is also made. 相似文献
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The vectorial nonparaxial four-petal Gaussian beam (FPGB) is introduced. The closed-form propagation expressions for the free-space propagation of FPGBs are derived and their more general applicable advantages are illustrated analytically and numerically. Some special interesting cases, in particular the paraxial one, are discussed. It is found that the parameter f = 1/kwo with the k being the wave number and wo being the waist width plays a crucial role in determining the nonparaxiallity of FPGBs. For small values of the f parameter the paraxial approximation is allowable. In the nonparaxial regime the beam order n additionally affects the vectorial and nonparaxial behaviour of FPGBs. 相似文献
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采用复q参量法对脉冲厄米高斯光束在自由空间中的传输进行了分析.在振幅0阶和位相一阶近似条件下,得到其传播过程中载波位相近似公式.运用数值方法和近似公式进行对比研究,发现在脉宽大于5 fs或在远场情况下,两者符合较好.采用近似办法,分别研究了厄米函数阶次、束宽与位置对载波相位的影响.研究表明,在光轴上远场,载波相位趋近于-m+n+1π/2,其变化快慢与厄米函数阶次m+n+1成正比|束腰宽度越大,则载波相位变化越慢|另外,离光轴距离越远,其导致的载波相位越大,且最大位置都出现在z=ZRω0/3处. 相似文献
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采用复q参量法对脉冲厄米高斯光束在自由空间中的传输进行了分析.在振幅O阶和位相一阶近似条件下,得到其传播过程中载波位相近似公式.运用数值方法和近似公式进行对比研究,发现在脉宽大于5 fs或在远场情况下,两者符合较好.采用近似办法,分别研究了厄米函数阶次、束宽与位置对载波相位的影响.研究表明,在光轴上远场,载波相位趋近于-(m+n+1)π/2,其变化快慢与厄米函数阶次(m+n+1)成正比;束腰宽度越大,则载波相位变化越慢;另外,离光轴距离越远,其导致的载波相位越大,且最大位置都出现在z=Z_R(ω_0)/3处. 相似文献
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导出了高斯光束在梯度负折射率介质中的ABCD矩阵,据此得到光束在此介质中的传输模型.并利用此模型分析了高斯光束在梯度负折射率介质中的传输特性,发现它能产生空间孤子及呼吸子形式的传输,并发现光束的束腰半径不一定是最小束宽半径.还研究了梯度系数对介质聚焦能力的影响,据此可以设计出相应聚焦能力所需要的折射率分布.最后分析了传输时高斯光束曲率半径的变化情况,与光束束宽半径的变化显著不同,曲率半径始终从无穷大开始,然后产生一个个周期性的变换. 相似文献
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In-vacuum propagation of a polychromatic Gaussian beam emitted by a dispersive laser resonator and its passage through thin plates are studied under following assumptions: optical fields are stationary and plane-polarized, the paraxial wave equation is valid for each monochromatic component of the beam, the waist position and the Rayleigh range depend on wavelength and diffraction edge effects are negligible. Mathematical expressions for beam radius, divergence, beam parameter product and beam propagation factor are obtained. The use of thin plates for waist position achromatization is analyzed. 相似文献
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Gaussian wave formalism model for propagation of charged-particle beam through a first-order optical systems 下载免费PDF全文
An elliptical Gaussian wave formalism model of a charged-particle beam is
proposed by analogy with an elliptical Gaussian light beam. In the paraxial approximation, the charged-particle beam can be described as a whole by a complex radius of curvature in the real space domains.
Therefore, the propagation and transform of charged-particle beam
passing through a first-order optical system is represented by the
\textit{ABCD}-like law.As an example of the application of this model, the relation between the beam waist and the minimum beam spot at a fixed target is discussed. The result, well matches that from conventional phase space model, and proves that the Gaussian wave formalism model is highly effective and reasonable. 相似文献