平顶高斯光束经含失调圆孔光阑的失调光学系统的传输特性

为分析平顶高斯光束通过光学系统传输时圆孔光阑失调和光学元件失调对平顶高斯光束传输特性的影响,利用失调圆孔光阑的近似展开式和适用于失调光学系统的广义衍射公式,得出了平顶高斯光束经含失调圆孔光阑的失调光学系统传输的近似解析式,给出了输出光束场分布与光束参量、光阑孔径尺寸、光阑和光学元件失调量等的定量关系.针对特定光学系统定量分析了各失调量对输出光束场分布的影响,结果表明各元件失调都对输出光束强度分布产生较大影响.但在各失调量较小的情况下,透镜失调对输出光束传输特性的影响比光阑失调对输出光束传输特性的影响更明显.     

平顶高斯光束经含失调圆孔光阑的失调光学系统的传输特性

为分析平顶高斯光束通过光学系统传输时圆孔光阑失调和光学元件失调对平顶高斯光束传输特性的影响,利用失调圆孔光阑的近似展开式和适用于失调光学系统的广义衍射公式,得出了平顶高斯光束经含失调圆孔光阑的失调光学系统传输的近似解析式,给出了输出光束场分布与光束参量、光阑孔径尺寸、光阑和光学元件失调量等的定量关系.针对特定光学系统定量分析了各失调量对输出光束场分布的影响,结果表明各元件失调都对输出光束强度分布产生较大影响.但在各失调量较小的情况下,透镜失调对输出光束传输特性的影响比光阑失调对输出光束传输特性的影响更明显.     

高斯光束通过含失调窄缝光阑的失调光学系统的传输特性

 利用硬边窄缝光阑的近似展开式和适用于失调光学系统的广义衍射公式,得出了高斯光束经含失调窄缝光阑的失调光学系统传输的近似解析式。模拟结果表明输出光束场分布与光束参量、光阑尺寸、ABCD矩阵元、光阑失调量和光学系统失调量有关。针对给定的光学系统和高斯光束定量分析了各失调量对输出光束场分布的影响,结果表明:光阑横向位移、光学系统横向位移和角位移均引起垂直于z轴截面内明显的光强非轴对称分布。当光阑半宽度为1 mm时,光阑的衍射作用使腰斑半径为0.5 mm的高斯光束产生-1.586π～1.465π范围的相对相移,且光阑横向位移、光学系统横向位移和角位移均引起焦平面前后相对相移的迅速变化。随光阑宽度变小,各失调量对输出光束特性的影响越明显。     

菲涅尔波带片对高斯光束的变换

从波带片的特性出发研究高斯光束通过波带片的聚焦特性。用失调望远系统的失调量变化调节出射光束聚焦点的位置，并对聚焦点的变化范围和光斑大小进行描述，最后对波带片对高斯光束聚焦特性进行评价。     

环状光束通过像散透镜的变换特性

 基于Tovar提出的平顶多高斯光束模型,给出了环状光束模型。利用广义惠更斯-菲涅耳衍射积分理论,对环状光束通过像散透镜后的传输和聚焦特性进行计算和分析,并讨论了透镜像散对环状光束经透镜变换后对光束质量的影响。研究结果表明:环状光束通过像散透镜后变为非旋转对称光束;聚焦光强随着透镜像散系数的增大而逐渐减弱,聚焦光斑的方位仅由像散系数确定;在光束阶数和入射光波波长一定的情况下,环状光束通过像散透镜的变换特性和光束质量不仅与透镜像散系数有关,还与系统菲涅耳数有关,像散系数增大或菲涅耳数减小时,光束质量变差。     

余弦平方高斯光束通过无光栏透镜的梯度力

基于Collins公式推导了余弦平方高斯光束通过无光栏透镜光学系统聚焦后的光强分布及梯度力,采用数值模拟分析梯度力分布及光阱的数量、位置及尺度随光束参数、光束入射距离及系统菲涅耳数的变化。结果表明:光束相关参数b越大光阱的数量越多,光阱的位置随光束入射距离而改变,大小随系统菲涅耳数的增加而减小,但不影响其位置。     

贝塞耳函数调制的高斯光束通过有光阑ABCD光学系统的传输

基于惠更斯菲涅尔广义衍射积分,对变量为径向平方的贝塞耳函数调制的高斯光束(QBG光束)通过有圆孔光阑限制的一阶ABCD光学系统的传输进行了研究.采用将圆域函数可表示为复高斯函数叠加的方法,推导出了普适的场分布解析公式,以QBG光束通过有圆孔光阑限制的薄透镜系统为例进行了分析与讨论,数值计算结果证明了本文所用方法的优点,所得结果与直接用广义衍射积分公式进行复杂的数值计算结果完全一致 关键词： QBG光束 光阑 ABCD光学系统 传输特性     

飞行光学导光系统中的空气热透镜效应

研究了激光加工用大功率ＣＯ２激光束在飞行光学导光系统中传输所产生的空气热透镜效应。实验发现当飞行光学导光系统中的空气静止时将产生空气热透镜效应,而充以一定压力的压缩空气却可以消除空气热透镜效应,实验表明无热透镜效应时,光束遵循高斯光束传输规律,而秀热透镜效应时,光束偏离高斯光束的传输规律,并影响到激光束聚焦焦点的大小和位置。另外通过激光空气热透镜效应的非线性模型计算了热透镜效应所引起的光束传输相对     

双环贝塞尔-高斯径向偏振光束经介质分界面的强聚焦

基于矢量德拜理论,研究了贝塞尔-高斯径向偏振光束经过衍射光学元件(DOE)和高数值孔径(NA)透镜组成的光学系统后经介质分界面的强聚焦特性。设计DOE的参数对入射的贝塞尔-高斯径向偏振光束进行调制,在聚焦场中能得到沿光轴方向的三维多点光俘获结构-光链。研究结果表明,入射光束的拦截比(即透镜孔径半径与入射光束束腰半径比)、数值孔径和聚焦场介质折射率都会影响光束的强聚焦特性。当光束的拦截比增大到一个值时,聚焦场的光链会转变成暗通道,并且在不改变暗通道宽度的情况下,暗通道的长度会随着介质折射率的增大而增长。     

克尔效应对高斯光束聚焦特性的影响

利用菲涅尔—基尔霍夫衍射积分公式,研究薄片近似情况下的Kerr效应带来的波前畸变对高斯光束聚焦特性的影响.在相位延迟为－2~2 rad的范围内进行的模拟计算表明：正Kerr效应能提高高斯光束的聚焦强度、增大相对焦移量、提高聚焦光束的焦平面桶中功率和降低几何焦平面的峰值光强;而负Kerr效应,则会降低聚焦强度、增大相对焦移量、降低聚焦光束的焦平面桶中功率和几何焦平面的峰值光强.可以通过增大光束菲涅尔数来抑制Kerr效应对聚焦特性的影响.     

Propagation of high-order Bessel–Gaussian beam through a misaligned first-order optical system

The generalized diffraction integralis used to derive a generalized formula for high-order Bessel–Gaussian beams (HBGBs) through a misaligned first-order ABCD optical system. It is found that, when a HBGB propagates through a misaligned optical system, the beam shape of the output beam is unchanged. However, the center of the output beam is deviated from the optical axis, forming a decentered HBGB. The position of the output beam may be controlled by adjusting the misaligned parameters. Based on the derived formula, the diffraction patterns of HBGBs propagating through a simple misaligned lens system have been calculated numerically. These results may be useful in the application of laser beams for trapping and manipulating a wide variety of particles.     

Propagation Effect of Hollow Gaussian Beams Passing through a Misaligned Optical System

A generalized formula of hollow Gaussian beams through the first-order misaligned ABCD systems is derived by using the generalized diffraction integral formula. It is shown that the hollow Gaussian beam passing through the misaligned system becomes a decentred hollow Gaussian beam. The propagation properties of the output beam are investigated when it propagates through a simple misaligned lens system. These results provide a powerful theoretical tool for applications of optical traps.     

Propagation of a Lorentz-Gauss beam through a misaligned optical system

Based on the generalized integral formula and the convolution theorem of the Fourier transform, an analytical propagation formula of a Lorentz-Gauss beam passing through a misaligned paraxial optical system is derived. As numerical examples, the propagation properties of a Lorentz-Gauss beam through a misaligned thin lens with the lateral displacement and the angle displacement are graphically illustrated, respectively. The influences of the lateral displacement and the angle displacement of the misaligned thin lens on the normalized light intensity and the phase distributions are also examined, respectively.     

洛伦兹光束经光阑失调傍轴光学系统的传输

基于广义衍射积分公式和光阑函数的复高斯展开,导出了一洛伦兹光束经一个带圆形光阑失调傍轴光学系统的近似解析传输公式.作为一般公式的特例,还给出了洛伦兹光束经一无光阑失调傍轴光学系统的解析传输式.作为数值计算的例子,运用所得到的公式分析了洛伦兹光束经带光阑失调薄透镜的传输特性.结果表明：不同强度的衍射即圆形光阑半径的大小明显影响衍射光束的归一化强度分布及其传输变化规律. 关键词： 洛伦兹光束 失调傍轴光学系统 光束传输     

Off-axis flat-topped multi-Gaussian beam and its propagation through paraxial optical system

Off-axis flat-topped multi-Gaussian beam is proposed as an extension of flat-topped multi-Gaussian beam. The electric field of off-axis flat-topped multi-Gaussian beam is expressed as a superposition of a series of off-axis Gaussian beams. Propagation formulae for off-axis flat-topped multi-Gaussian beam through aligned and misaligned optical system are derived. As a numerical example, propagation properties of off-axis flat-topped multi-Gaussian beam in free space and through a misaligned thin lens are discussed.     

Propagation of a Laguerre–Gaussian beam through a slightly misaligned paraxial optical system

Based on the generalized diffraction integral formula for treating the propagation of a laser beam through a slightly misaligned optical system in a cylindrical coordinate system, an analytical formula for a Laguerre–Gaussian beam passing through such an optical system is derived. Furthermore, an approximate analytical formula is derived for a Laguerre–Gaussian beam passing through an apertured slightly misaligned optical system by expanding the hard aperture function as a finite sum of complex Gaussian functions. Some analytical formulas are also given for a flattened Gaussian beam by expanding its field as a superposition of a finite series of Laguerre–Gaussian beams. PACS 42.25.Bs; 41.85.Ew; 41.85.Ct     

Propagation of anomalous hollow beam through a misaligned first-order optical system

In this paper, we consider the propagation of an anomalous hollow beam passing through the first-order ABCD optical system. Based on the generalized diffraction integrals, a general propagating formula of anomalous hollow beam is derived. Based on the derived formula, the propagation properties of anomalous hollow beam through the misaligned optical system are numerically illustrated. From the numerical results we can get that when an anomalous hollow beam propagates through a misaligned optical system, the shape of the output beam changes as the propagation distance increases, and the center of the output beam is deviated from the optical axis. The position of the output beam is effected by the misaligned parameters, and can be controlled by adjusting them. This method provides a convenient tool for studying the propagation and transformation of an anomalous hollow beam through the misaligned optical system.     

Propagation of a hollow Gaussian beam through a paraxial misaligned optical system

Based on the generalized diffraction integral formula for treating the propagation of a laser beam through a paraxial misaligned optical system in the cylindrical coordinate system, we obtain an analytical formula for a hollow Gaussian beam passing through a paraxial misaligned optical system. Furthermore, we also obtain the approximate analytical formula for a hollow Gaussian beam passing through a paraxial circularly apertured misaligned optical system by expanding the hard aperture function into a finite sum of complex Gaussian functions. As a numerical example, the propagation properties a hollow Gaussian beam through a misaligned thin lens are studied numerically.