首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到10条相似文献,搜索用时 125 毫秒
1.
The dependence of the beam propagation factor (M 2 parameter) with the absorbed pump power in the case of monolithic microchip laser under face-cooled configuration is extensively studied. Our investigations show that the M 2 parameter is related to the absorbed pump power through two parameters (α and β) whose values depend on the laser material properties and laser configuration. We have shown that one parameter arises due to the oscillation of higher order modes in the microchip cavity and the other parameter accounts for the spherical aberration associated with the thermal lens induced by the pump beam. Such dependency of M 2 parameter with the absorbed pump power is experimentally verified for a face-cooled monolithic microchip laser based on Nd3+ -doped GdVO4 crystal and the values of α and β parameters were estimated from the experimentally measured data points.  相似文献   

2.
潘平平  张彬 《物理学报》2011,60(1):14215-014215
基于广义惠更斯-菲涅尔原理以及大气湍流理论,推导出部分相干光束在大气湍流中传输的光束传输M 2因子的解析表达式.定量分析了表征大气湍流参数的折射率结构常数 C2n和涡旋内尺度 l 0对 M 2因子的影响,并由此提出了一种通过实验测量大气湍流中光束的 M 2因子,进而确定出大气湍流参数的新方法.研究结果表明,由于大气湍流对相干性好的光束影响更为明显,在测量中可采用具有高相干性的基模高斯光束作为测量光源,而测量装 关键词: 2因子')" href="#">光束传输 M 2因子 大气湍流参数 湍流折射率结构常数 湍流涡旋内尺度  相似文献   

3.
A simple method to determine the thermal focal length of LD end-pumped solid-state laser with stable resonator is presented. The M2 factor describing the quality of the beam can be obtained by scanning a slit through the multi-mode Gaussian beam field. The waist width of the beam and the corresponding TEM00 under the same parameters of laser are then deduced through the law of multi-mode Gaussian beam propagation. Based on the standard matrix theory of stable resonator, the thermal focal length of the gain medium can be easily achieved. To show the application of this approach, the thermal focal length of an LD pumped Nd:YVO4 laser is measured and the experimental results are in agreement with the theoretical prediction.  相似文献   

4.
李晓庆  季小玲 《物理学报》2011,60(9):94206-094206
基于广义截断二阶矩法,推导出了截断部分相干厄米-高斯(H-G)光束的广义M2G因子的解析表达式. 截断完全相干H-G光束、截断高斯谢尔模型(GSM)光束以及截断高斯光束可以做为本文结果的特例给出. 研究表明:截断部分相干H-G光束的广义M2G因子与截断参数δ,模阶数m以及相干参数α有关. 当δ非常小时,M2关键词: 截断部分相干厄米高斯光束 M2G因子')" href="#">广义M2G因子 广义截断二阶矩法  相似文献   

5.
提出了厄米-高斯光场的M2因子矩阵.引入束半宽平方的交叉项、M2因子的交叉项,理论推导出了在同一坐标系下光场旋转一定角度后的M2因子矩阵,数值模拟了与M2因子矩阵有关的各参数随光场旋转角度变化的规律,给出了光场的M2因子矢量点随光场旋转角度变化的轨迹曲线.计算结果与理论推导结果相符,证实了利用M2因子矩阵可以将旋转前后的二维厄米-高斯光场用旋转矩阵统一起来.该方法可推广到对一般的二维高阶高斯光束的光束质量的理论分析上,具有普适性,对光束质量的实际测量有重要的理论指导意义. 关键词: M2因子矩阵')" href="#">M2因子矩阵 厄米-高斯光束 非对称激光束 矩阵光学  相似文献   

6.
M2 is now widely used to characterize the quality of laser radiation. In the paraxial approach the inequality M21 holds, if M2 is defined by the second moments. Nevertheless, in some publications M2<1 is presented, either theoretically or experimentally (Wang et al., Optik 1995;100(1):8; Lu et al., Optik 1995;100(2):91; Wang et al., Optics and Laser Technology 1999;31:151). In particular, it is stated that for a superposition of axially shifted Gaussian spherical beams, M2 can become smaller than one (Wang et al., Optics and Laser Technology 1999;31:151). These problems with M2 are briefly summarized.  相似文献   

7.
利用一束波长为36055nm的激光,通过(3+1)共振多光子电离方法制备纯净的且处于X2Π1/2,3/2(000)态的N2O+离子,用另一束激光激发所制备的离子到第一电子激发态A2Σ+的不同振动能级,然后解离,通过检测解离碎片NO+强度随光解光波长的变化,得到了转动分辨的N2 关键词: 2O+离子A2Σ+电子态')" href="#">N2O+离子A2Σ+电子态 共振增强多光子电离 光解碎片激发光谱 光谱常数  相似文献   

8.
A detailed study of the generalized M2 factor of hard-edged diffracted beams based on the truncated second-order moments method, asymptotic analysis and self-convergent beam width approach is performed. The dependence of the generalized M2 factor on the parameters characterizing the spatial profile, and beam truncation, etc. is analyzed.  相似文献   

9.
We report on fundamental and intracavity frequency-doubled emission in a miniature Nd:YVO4 (3×3×1 mm) laser. A maximum slope efficiency of ηs=58.6%, with optical efficiency of η0=53.0% at 780 mW pump power was realized in a TEM00 output beam. To obtain the optimum pump-beam focusing conditions we applied a new formalism in which the pump-beam propagation in the active medium was described by its M2 factor. A good agreement between theoretical predictions and experimental results was observed. In second-harmonic regime, obtained by a KTP crystal, 230 mW green power that corresponds to 54% nonlinear conversion efficiency was reached.  相似文献   

10.
Starting from the space-time Wigner distribution function and taking the Gaussian Schell-model pulsed beam as a typical example, the M2 factor of partially coherent ultrashort pulsed beams is studied. It is shown that the M2 factor increases with increasing bandwidth and decreases with increasing spatial correlation. Furthermore, for chirped pulse, the M2 factor increases as the chirp parameter increases.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号