基于空间光调制器的轴向动态三维达曼阵列

项目名称： 基于空间光调制器的轴向动态三维达曼阵列

项目编号： No.61308077

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 余俊杰

作者单位： 中国科学院上海光学精密机械研究所

项目金额： 25万元

中文摘要： 传统激光扫描技术是利用物镜的单个聚焦光斑机械式逐点扫描获得物质的微观结构信息或产生激光与物质的局域作用，因而系统效率低、稳定性和可靠性差，尤其对高数值孔径油浸聚焦系统更是如此。本项目拟通过空间光调制器（SLM）在聚焦物镜的入射光瞳中引入二次球面相位项，从而改变物镜聚焦光斑的轴向位置。通过连续调节二次球面相位的离焦水平，即可实现聚焦光斑的轴向扫描。结合我们提出的三维达曼光栅技术[Appl. Opt.51,1619(2012)]，我们将这种轴向扫描的单点聚焦光斑拓展为三维空间分布的焦斑阵列，从而在传统的激光扫描技术中实现轴向扫描的三维达曼阵列,极大提高系统的扫描效率。同时，利用SLM的可编程性实时调节二次相位项来实现达曼阵列整体轴向动态扫描，避免了传统的机械式扫描，从而极大地提升系统的稳定性和可靠性。因而，这种基于SLM的轴向动态三维达曼阵列在各种激光扫描成像或处理技术中有广泛的应用前景。

中文关键词： 三维达曼阵列；轴向扫描；达曼编码；光学涡旋；

英文摘要： It is well-known that, in traditional point-by-point laser scanning techniques, the single focus spot generated by focusing a laser beam via an objective is mechanically scanning to obtain micro-/nano-scale structure information or induce local laser-material interaction in a small voxel. Because of these properties, the traditional point-by-point scanning techniques inherently possess low efficiency, weak stability and poor robustness, especially for those high numerical-aperture (NA) oil-immersion systems. Here, we propose a scheme to modulate the axial position of the focus spot by introducing a quadratic phase into the pupil plane of the focusing objective based on a spatial light modulator (SLM). Then, by changing the defocus level of the quadratic phase, one can obtain the focus spot scanning along the axial direction. By combining the technique of 3D Dammann gratings proposed by us [Appl. Opt. 51, 1619 (2012)], one can realize a 3D Dammann array of the focus spots scanning along the axial direaction, which will drastically improve the laser processing efficiency. Moreover, the scanning manner is realized by continuously changing the defocus level of the quadratic phase via a programmable SLM, and thus the system should be much more stable and robust because there is no mechanical scanning any more. Theref

英文关键词： 3D Dammann array；Axial shifting；Dammann encoding；Optical vortex；