主光轴平行于基底的微透镜阵列制作与测试

Fabrication and Measurement of Microlens Arrays with Primary Optical Axis Paralleled to Wafers

应用SU-8负性感光胶的独特性能,采用水浴倾斜紫外光刻的方法,优化工艺参数,构造出主光轴平行于基底的球面微透镜阵列,其单个透镜的直径约为200μm。利用激光扫描共聚焦显微镜(LSCM)对微透镜的表面形貌及曲率半径进行测量,并搭建光学观测平台,测得透镜焦距并观察成像效果。经观测,所加工球面微透镜具有较好的表面形貌和成像效果。基于此方法加工的微透镜阵列,主光轴平行于基底,因而便于与其他光学系统进行片上集成,完成对光线的聚焦,最终实现光开关、扫描成像等功能。此微透镜阵列也将集成在微流式细胞仪上,用于样本流的荧光检测,可极大提高检测精度。

Through applying the special features of SU-8 negative photoresist,using the method of water bath oblique UV lithography and optimizing the processing parameters,the spherical microlens arrays with the primary optical axis paralleled to the wafer were fabricated.The diameter of a single lens is about 200 μm.The surface morphology and the curvature radius of the microlens were measured with the laser scanning confocal microscope（LSCM）,and the optical observation platform was built to measure the lens focal length and observe the imaging results.It is observed that the lens has a good surface morphology and imaging results.This method makes the primary optical axis of the microlens array parallel to the wafer,and makes it easy to be integrated into on-chip optical systems,complete the light focus,and eventually realize features such as the light switch and imaging.The microlens arrays will also be incorporated to the micro flow cytometry for fluorescence detections in sample streams,increasing the detection accuracy greatly.