光子学报, 2019, 48 (3): 0314001, 网络出版: 2019-04-02
随机位相菲涅耳透镜阵列激光束匀化
Beam Homogenization of a Fresnel Lens Array with a Randomly Distributed Phase for Laser Beams
激光束均匀化 单模高斯光束 随机位相 菲涅耳透镜阵列 干涉 Laser beam homogenization Single-mode Gaussian beams Random phase Fresnel lens array Interference
摘要
为降低干涉带来的影响, 将一种随机位相分布引入菲涅耳透镜阵列, 对阵列中每一个菲涅耳透镜施加0或π的二值化位相变化, 打乱阵列位相的周期性排布, 减少微透镜后多光束在匀化面干涉带来的影响.通过数值计算对激光束的匀化过程进行了模拟, 设计的菲涅耳透镜口径为0.5 mm, 焦距为6 mm, 阵列数目为20×20, 光斑整体均匀度达到90%, 光束能量利用率达到96%.利用设计和制备的16台阶随机位相型菲涅耳透镜阵列对1 064 nm波长的激光光束进行匀化, 均匀度为83%, 光束能量利用率为89%.研究结果表明, 通过引入随机位相可有效减少干涉带来的影响, 提高微透镜阵列对单模高斯光束的匀束效果.
Abstract
To eliminate the multi-beam interference, a binary and randomly distributed phase was introduced to the Fresnel lens array and a binary phase change of 0 or π is applied to individual Fresnel lens. This change in phase disrupts the phases of the periodic beams, and therefore reduces the effect of multi-beam interference on the homogenized plane. The numerical simulation of the laser beam homogenization were carried out using the Fresnel lens with an aperture of 0.5 mm and the foci of 6 mm, and the array number of 20×20. The simulation results show that the overall uniformity of the target plane is calculated as 90% and the beams energy efficiency can be up to 96%. The designed Fresnel lens array was fabricated using microelectronic technologies. The measured uniformity of the homogenized laser beams at a wavelength of 1 064 nm was 83%, and the beams energy efficiency was 96%. Our results indicate that the introduction of the binary and randomly distributed phase to the periodic microlens array can effectively decrease the influence of interference and improve the uniformity of homogenization of single-mode Gaussian beams.
裴宪梓, 梁永浩, 王菲, 朱效立, 谢常青. 随机位相菲涅耳透镜阵列激光束匀化[J]. 光子学报, 2019, 48(3): 0314001. PEI Xian-zi, LIANG Yong-hao, WANG Fei, ZHU Xiao-li, XIE Chang-qing. Beam Homogenization of a Fresnel Lens Array with a Randomly Distributed Phase for Laser Beams[J]. ACTA PHOTONICA SINICA, 2019, 48(3): 0314001.