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在激光束参数测量中,常常使用针孔扫描法来测量光束光强的轮廓分布,但该法要求扫描的针孔必须通过光斑中心,否则会引起较大的测量误差,另外,若被测光斑较小,所需针孔就较小,亦增加了测量的难度。本文介绍利用狭缝作一维扫描,同样可以得到高斯光束的光强分布,但是避免了对中的麻烦,而且由于通过狭缝的光能较强,方便了操作,提高了信噪比。设高斯光束横向光强分布为式中,I_0为光束中心点的光强,ω为光斑半径。若扫描狭缝宽为Δ,缝中心在x′处,缝长远大于光斑直径,那末通过狭缝的光能是 相似文献
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报道了研制的激光束二维强度分布测量装置,实现了从红外到可见的激光束二维强度分布测量,给出直观的激光束远场立体花样和平面分布等高能量图,进一步用该装置测量出激光能量,文章最后给出了标定方法和结果. 相似文献
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深入分析了方板构型的电光开关晶体在高功率载荷条件下的热畸变行为,讨论了光强分布对热效应的影响。以KDP晶体为例,分别计算了激光束光强为高斯分布和均匀分布时晶体的温升、相应的热应力分布、波前畸变以及热退偏。结果表明,光强的分布形式对波前畸变和热退偏的影响是不同的。相对于光强均匀分布的激光束,高斯光束减缓了光斑边沿处的温度梯度,产生的热应力较小,因此可以减弱热退偏效应;另一方面,在光束口径范围内,高斯光束产生了附加的温度分布非均匀性,因而波前畸变会大一些。 相似文献
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在大光斑高能激光光强时空分布参数测试方法中,阵列探测器测试法是一种较好的方法。它能测量出激光束的总能量和强度时空分布。阵列探测器主要由探头、数据采集系统和软件处理系统等三部分组成。探头采用高吸收材料制作,其表面按一定规律分布着多个独立探测单元,能同时测量高能激光束的能量及其空间分布。系统不可避免地存在测量误差,为消除系统误差,需要对系统进行标定,包括能量系数标定和探测单元的响应系数标定等。 相似文献
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激光大气传输束心抖动概率分布 总被引:2,自引:0,他引:2
用概率理论研究了湍流大气中传播激光束心抖动概率分布和抖动导致点孔检测平均光强起伏概率分布。结果表明,二维束心抖动概率满足Rician分布而点孔检测平均光强的起伏满足Gamma分布。 相似文献
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用刀口法测量氦氖激光基横模 总被引:1,自引:0,他引:1
介绍研究氦氖激光基横模的刀口法测量原理,给出实验装置和实验结果,这种方法能够证实氦氖激光基横模的光强分布是高斯分布,能够确定光斑的大小。 相似文献
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介绍一种用温度自补偿电阻应变计测量激光引起的固体的快速热应变的方法,并对铝合金材料进行了实际测量。结果表明,用温度自补偿电阻应变计方法测量秒量级强激光辐照下固体材料的快速热应变是可行的。 相似文献
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提出用CCD漫透射成像法测量激光强度时空分布和激光功率,给出了测量原理, 简要叙述了装置总体结构,介绍了测量装置各部分,给出了散射屏的散射特性,重点分析了光路布局、镜头焦距、光圈、景深、滤光片的参数选择,介绍了数据处理软件,给出了激光强度分布测量实验结果。结果表明:漫透射成像法测量激光强度时空分布是可行的,该装置测量强度分布分辨力高达5 mm;测量功率准确、可靠,测量不确定度小于6%,使用方便,实现了在小空间内对大光斑进行功率和强度分布的同时准确测量。 相似文献
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A phase retrieval algorithm which only needs to measure the intensity distribution at two positions to be effective is used to reconstruct the laser wave-front.Results are obtained from the phase retrieval algorithm in the visible band and the effects of the measurement error on the phase retrieval process are simulated.The algorithm is not sensitive to absolute amplitude measurement error,but is sensitive to the relative distribution of light intensity. 相似文献
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利用可调谐激光吸收光谱技术(TDLAS),扫描多条吸收谱线以实现气体温度分布的测量。文章给出了温度分布测量的原理和方程离散化的方法,在气体浓度和压力均匀时,利用带约束最小二乘法计算得到温度分布。根据HITRAN中6 330 cm-1附近的4条CO谱线的参数,建立了温度在300和600 K时,路径长度均为55 cm的两段温度分布模型,模拟了测量误差与温度区间长度约束条件的影响。结果表明随着测量误差的增大和约束条件的减弱,计算结果误差相应增大。在5%的测量误差下,计算结果的最大误差为11%,平均误差为2.2%。以管式炉中的高温段和室温下的低温段作为两段温度分布模型进行试验。利用6 330 cm-1处的垂直腔面发射激光二极管(VCSEL)扫描得到的4条CO谱线,通过背景信号的三次多项式拟合得到基线,求出温度分布计算所需的光谱吸收率积分值。在四种情况下, 计算温度分布结果与模型误差分别为7.3%,6.5%,4.7%和2.7%。 相似文献
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E. O. Schulz-DuBois H. Koppe R. Brummer 《Applied Physics A: Materials Science & Processing》1980,21(4):369-376
After a brief survey of number fluctuations, a topic of current interest in light scattering research, the theory is developed
for a particular case of this type. A laser beam of Gaussian cross section illuminates a volume in which there is a fluctuating
number of identical particles. For incoherent detection the scattered intensities are additive. The interest centers on the
statistics of the total scattered intensity. Starting from the moment generating function, the distribution function of scattered
intensity is computed using two different methods. In an experiment designed to test the computed distributions, agreement
between theory and measurement is found if the mean particle number within the scattering volume exceeds 3. The experimental
procedure is described and some difficulties are explained which so far did not permit application of the theory for particle
numbers much below 3. 相似文献
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Simulation supported description of the local doping formation using laser chemical processing (LCP)
Andreas Fell Sybille Hopman Filip Granek 《Applied Physics A: Materials Science & Processing》2011,104(1):165-170
We present an enhanced model to describe the physics of laser chemical processing (LCP), a liquid jet guided laser technique,
for local doping processes applied to crystalline silicon solar cells. The main improvement of the numerical model is the
consideration of the inhomogeneous laser light intensity profile within the liquid jet cross section. Measurements of the
intensity profile show local superelevations of up to factor five compared to the average intensity. A measured intensity
profile was implemented into the numerical model and yields good agreement between simulated and measured dopant distributions.
Inhomogeneities of the spatial dopant distribution are observed and their impact on LCP line scans for producing doped lines
is investigated with respect to solar cell manufacturing. 相似文献
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A method of direct measurement of near-field phase and intensity distribution of laser diodes employing a single-mode fiber interferometer is proposed and demonstrated. The phase and intensity of the output beam of the laser in the vicinity of the output facet are measured directly via interferometry. Using a 980 nm laser diode as an example, we obtained a beam width of 0.9 and 3.6 μm at the output facet in the vertical and horizontal axes, respectively. In addition, the phase information of the output beam was also obtained by using interferometry. This technique is particularly useful for laser diodes whose near-field phases are difficult to measure directly. The measured vertical and horizontal wavefront radius of curvatures of a laser diode are in good agreement with the calculation from Gaussian beam theory. Detailed understanding and measurement of the near-field phase and intensity distributions of light sources and optical components are essential for micro-optic designs with better mode matching to minimize the insertion loss. 相似文献
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脉宽调制技术目前已广泛应用于高频电磁加热系统、开关电源等领域1,本文首次将脉宽调制技术用于激光扫描测量系统,解决了激光扫描测量中国不同材料对激光的散射光强不同、不同曲面对激光光强反射各异以及物体表面镜面反射等问题给测量精度带来的严重影响2,利用激光扫描系统中的摄象机直接作为光强反馈系统,实现了测量过程中的光强自动控制,有效地降低了光强饱和等问题给测量带来的误差. 相似文献