利用光斑图像特征确定飞秒激光有效烧蚀焦距

发布时间：2018-04-25 01:06

本文选题：飞秒激光 + 硅晶片烧蚀　；参考：《应用光学》2017年05期

【摘要】：为确定飞秒激光光束对微尺度结构的烧蚀深度,研究了给定功率条件下对应的激光束有效烧蚀焦距。提出采用激光焦点处获得的烧痕阵列图像及在离焦状态下提取烧痕图像特征,通过分析图像特征与离焦距离,获得激光束有效烧蚀焦距范围的方法。在激光束焦点附近的硅晶片表面烧蚀出斑痕阵列,向下逐渐减小焦距,采集硅晶片斑痕图像,提取斑痕平均像素面积及斑痕目标与背景之间的R分量灰度差,获得斑痕像素面积及灰度差随激光束焦距变化的曲线;向上逐渐增大焦距,提取并获得斑痕像素面积及灰度差随激光束焦距变化的曲线。结合激光束向下离焦阈值(633μm)及向上离焦阈值(993μm),确定20mW输出功率条件下,飞秒激光在硅晶片材料表面的有效烧蚀深度为360μm。采用中位值方法确定了激光束在硅晶片表面聚焦时的焦距为0.823mm。实验表明,激光烧蚀斑痕像素面积及灰度差与激光束焦距之间的关系能够客观地反映激光束有效烧蚀焦距的变化范围。
[Abstract]:In order to determine the ablation depth of femtosecond laser beams on microstructures, the effective ablation focal length of laser beams under given power conditions is studied. A method is proposed to obtain the effective ablation focal length range by analyzing the image features and the defocus distance by using the laser focus array images and extracting the image features in the defocus state. The speckle array is ablated on the surface of the silicon wafer near the focus of the laser beam, and the focal length is gradually reduced down. The average pixel area of the speckle and the R component gray difference between the speckle target and the background are extracted by collecting the speckle image of the silicon chip. The curve of speckle pixel area and grayscale difference changing with laser beam focal length is obtained, and the curve of speckle pixel area and gray difference changing with laser beam focal length is obtained. The effective ablation depth of femtosecond laser on the surface of silicon wafer is determined to be 360 渭 m under the condition of 20mW output power combined with the downward defocusing threshold of 633 渭 m and the upward defocusing threshold of 993 渭 m. The focal length of the laser beam focusing on the silicon wafer surface is determined to be 0.823 mm. by the neutral value method. The experimental results show that the relationship between the pixel area and gray level difference of laser ablation mark and the focal length of laser beam can objectively reflect the range of effective ablation focal length of laser beam.
【作者单位】：华北理工大学电气工程学院;卡尔加里大学机械及制造工程系;北京科技大学自动化学院;
【基金】：国家自然科学基金(71601039)
【分类号】：TN249;TN304.12

【相似文献】