平顶高斯模式宽带激光通过光阑的光强分布  

Intensity distribution of broadband laser with flattened-Gaussian mode passing through an aperture

作　　者：彭润伍[1] 李乐[1] 李亚捷[1] 谢海情[1] 唐立军[1] 

机构地区：[1]长沙理工大学物理与电子科学学院,长沙410114

出　　处：《激光技术》2013年第6期829-832,共4页Laser Technology

基　　金：湖南省教育厅高等学校科学研究重点资助项目(11A011);湖南省科技计划资助项目(2011GK3116);湖南省重点学科建设项目;湖南省高校科技创新团队计划资助项目

摘　　要：为了研究横向分布为平顶高斯模式的宽带激光通过硬边光阑系统的光强分布特性,采用衍射积分公式推导了平顶高斯模式宽带激光的每一频率分量在光阑系统中的传输公式,再通过傅里叶变换得到时间域的传输公式,详细分析了光阑和频带宽度对强度分布的影响。结果表明,近场光强在截断参量较大时,仍保持一定的平顶分布特性,但是随带宽的增加强度分布变窄;截断参量较小时强度呈高斯分布,并且带宽的变化对强度分布没有太大影响;然而在远场时截断参量较小情况下的光强分布也明显表现出随带宽增加而变窄的现象,但随着截断参量增大,这一变化趋势变缓。这些结果对平顶高斯模式宽带激光的应用具有重要参考价值。In order to study intensity distribution of a broadband laser with flattened-Gaussian transverse modes passing through a hard-edged aperture, the propagation expression of each frequency component of the broadband laser was deduced on the basis of the diffraction integral, and then the propagation expression in spatial domain was obtained by means of Fourier transform. Effect of the aperture and the bandwidth on the intensity distribution was analyzed. The results show that the intensity distribution keeps somewhat flattened profile and the profile become narrower with increasing bandwidth when the truncation parameter is large in the near field. When the truncation parameter is small, the intensity distribution is Gaussian profile and the bandwidth has little effect on the profile. In the far field, however, the profiie of the intensity also presents narrowing effect with increasing bandwidth when the truncation parameter is small and the narrowing effect tends to decrease with increasing truncation parameter. The results have significant value for applications of broadband laser with flattened-Gaussian transverse mode.

关 键 词：激光光学 宽带激光 衍射积分 硬边光阑 窄化现象 

分 类 号：O435[机械工程—光学工程]