查询词典 Fresnel integral

A general formula for computing the OTF of a defocused optical system is derived from the Kirchoff diffraction integration under an approximate condition which is weaker than the Fresnel condition.

本文从基尔霍夫衍射积分公式出发，在弱于菲涅耳条件的近似下，以高斯像面的像差量及系统的离焦量为参变量，导出了便于计算离焦光学系统的OTF的普遍算式。

Based on the full-width at half-maximum of optical pulse,one can estimate the radius of incident beams and Fresnel biprism's base angle.

根据所测飞秒脉冲的半高全宽，可估算所需光斑大小和菲涅尔双棱镜底角，为菲涅尔双棱镜的选择提供了理论依据。

Meanwhile,the relation among Fresnel biprism's base angle,refractive index,and the radius of incident femtosecond pulse beam was obtained.

基于单发频率分辨光学开关法的飞秒脉冲测量系统，理论推导光束经菲涅尔双棱镜分光与聚合产生的时间延迟，得到菲涅尔双棱镜底角、折射率和脉冲光斑半径的关系。

Pulse measurement ; grating eliminated no-nosense observation of ultrafast laser light E-fields ; Fresnel biprism ; full-width at half-maximum ; femtosecond beams

脉冲测量；单发频率分辨光学开关；菲涅尔双棱镜；半高全宽；飞秒激光

After comparing the laser intensity absorbed due to the inverse Bremsstrahlung absorption of the plasma with that absorbed due to the Fresnel absorption on the keyhole wall, the different effects of the two energy absorption mechanisms on forming and keeping the keyhole were analyzed.

通过比较小孔内等离子体的反韧致辐射吸收的激光功率密度和小孔孔壁上的多次反射吸收的激光功率密度，分析了两种能量吸收机制在小孔形成和维持过程中所起的不同作用。

In the new design, Fresnel theory and Brewster′s law were used.

在设计中应用了菲涅耳理论、布儒斯特定律。

The diffraction theory of Kirchhoff is applied to the four-pinhole aperture diffraction screens, the intensity, the zero-contour of the real and imaginary parts of complex amplitude and the phase distribution in deep Fresnel diffraction region are simulated, and it is found that the bright spots in interference field show central symmetry distribution. When the observation plane close to the diffraction screen, the zero-value points of light intensity can form line segment, on which the eccentricities of the light intensity isoline are close or equal to 1, the intensity changes very fast on both sides of the zero-line of light intensity.

利用基尔霍夫衍射理论计算了四圆孔径衍射屏在菲涅尔深区形成的的干涉光场的强度、零值线和相位的分布，发现干涉光场亮斑关于中心呈对称分布，在距离衍射屏较近的观察面上，光强值为的零点组成光强零值线段，该线段上光强等值线的离心率都接近或等于1，其两侧的光强值变化非常剧烈。

Three LEDs biology light sources with different intensity for cell or tissue culture have been developed in the third part of this thesis. A concave lens to expand the beams of light, to focus the rays of light and an array of LEDs being set in the sphere connected with Fresnel lenses are three newly-designed in our systems.

实际测试数据表明：低强度光源输出的辐射照度范围为0.0021—0.9961(W／m~2)，在直径20mm的照射面积内所测辐射照度的标准偏差为0.02W／m~2(n=40，Mean：0.71 W／m~2)；中等强度光源输出的辐射照度范围为0.3579—11.2286(W／m~2)，在直径30mm照射面积内所测辐射照度的标准偏差为0.02W／m~2n=60，Mean：6.37 W／m~2；较高强度光源输出的辐射照度范围为17—110(W／m~2，在直径40mm照射面积内所测辐射照度的标准偏差为0.02W／m~2(n=80，Mean：71.54 W／m~2)。

According to the generalized Huygens-Fresnel principle, the peculiarity of laser beam intensity distribution is simulated under the different condition such as refractive index of atmospheric structure constant and transmission pace and laser wavelength.

根据广义惠更斯-菲涅耳原理，对TEM00模和TEM10模光束在不同大气折射率结构常数、传输距离和传输激光波长条件下的光强分布特性进行数值模拟。

Digital holography ; Microscopic digital holography ; Wave front reconstruction ; Fresnel approximation ; Convolution method ; Angular spectrum theorem

数字全息；显微数字全息；波前重建；菲涅耳近似；卷积法；角谱方法

More direct, directer ; most direct, directest

径直的，笔直的

Do you know how to use a chain saw?

你知道如何使用链锯吗？