基模激光光源的光强高斯分布,使得激光标线器的线斑光强分布不均匀。提出了一种用TEM20,TEM40类的高阶模光源代替基模光源的方法。这类高阶模的一个正交方向上的光强分布为几个高斯轮廓的叠加,相对于基模光强的单个高斯分布提高了均匀性。当相邻两高斯分布间间距越小时,高阶模光强分布越均匀。实验通过使激光二极管(LD)相对于腔模轴线横向偏离得到高阶模。通过对横向偏距的精确控制,来控制相邻高斯分布的间距。在激光标线器1 m工作距离处,分别在基模和高阶模作为光源的情况下测得线斑光强数据。数据表明,高阶模光强分布的多瓣叠加特性能提高线斑的光强分布均匀性。

Aimed at un-uniform line intensity of laser beam line generator caused by Gaussian distribution of based mode intensity, a new method replacing the based mode with higher-order mode such as TEM20, TEM40 was presented in this paper. The intensity distribution at one of the orthogonal directions of such higher-order mode is the overlapping of several Gaussian distributions. It is more even than single Gaussian intensity distribution of based mode. More short the distance between the near Gaussian apices, more even the intensity distribution of the higher-order mode. The higher-order modes were got by moving transversely laser diode (LD) apart from the axis of the resonator in the experiment. The distance between the near Gaussian apices is controlled accurately by controlling accurately the divergence of LD. At 1 m working distance of laser beam line generator, the data of line intensity were obtained when based mode and higher-order mode incidence acted as the source respectively. The data proved that the overlapping intensity distribution of higher-order mode could improve the line intensity uniformity.