Author Affiliations
Abstract
1 Laser Micro/Nano-Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China
2 Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511, USA
A simple and repeatable method to fabricate high-aspect-ratio (HAR) and high-quality microgrooves in silica is reported. The method consists of two steps: (1) formation of laser-modified regions by femtosecond Bessel beam irradiation, and (2) removing laser-modified regions through HF etching. Uniform, straight microgrooves can be fabricated and the highest aspect ratio that can be reached is ～52. The phenomenon is attributed to the uniform energy distribution in the long propagation distance, which leads to the long and uniform laser-modified regions and subsequent HF acid etching of laser-modified regions with high selectivity. This method will have potential applications in fabrication of HAR microgrooves in transparent materials.
140.3390 Laser materials processing 230.4000 Microstructure fabrication 320.5540 Pulse shaping Chinese Optics Letters
2015, 13(4): 041405
针对序列图像配准问题，提出一种快速低存储开销配准算法。首先，生成一系列与具体图像内容无关的特征点。而后，使用正向-反向跟踪来获取稳定的特征点对,其中，正向跟踪用于获得所有可能的特征点对，反向跟踪用来得到正向-反向误差，并且利用此误差来获取最终稳定的特征点对。最后，在稳定特征点对的基础上通过归一化直接线性变换计算得到可用于图像配准的单应矩阵。实验表明该算法能够提供与优秀的传统算法相当的配准性能。由于该算法对序列中图像之间的连续性进行了充分利用，不仅降低了存储开销，还提高了运算速度。对480×360的序列而言，该算法需要的存储开销仅为421 kB，且运算速度达到32 帧/s。
图像序列 图像配准 单应矩阵 快速算法 低存储开销 image sequence image registration homography fast algorithm memory-saving
