微尺度光栅的激光制备方法研究及应用

发布时间：2019-01-11 21:26

【摘要】：随着微机电系统的发展应用,微观力学的研究日益成为热点。光测力学测量方法具有非接触、全场性、高精度等优点,被广泛应用到不同领域的材料和结构的变形测量中。光栅作为变形测量中重要的传感元件,它的制备一直备受关注。因此,如何准确定位到测量区域并快捷地制备光栅成为了重要的问题。不同的制栅方法有不同的优点和局限性。激光具有非常高的瞬时功率,热影响区小,具有很高的微加工质量和精度。同其他制作光栅方法相比,激光刻蚀省去了制作模板与显影等工序,可以直接刻蚀,制作面积可调节,且定位准确。本论文分别采用纳秒激光和飞秒激光,系统的研究了微尺度光栅制备方法。主要研究内容如下:(1)研究了基于光栅的几何相位法(GPA)和扫描电子显微镜(SEM)云纹法,用于不同频率与面积的光栅结构表征。推导并模拟验证了基于相位的二维傅立叶变换的光栅频率表征方法。建立了SEM云纹法中放大倍数和参考栅频率的关系。(2)研究了纳秒激光制作微尺度光栅方法。从基本的刻蚀线段入手,对比分析了不同材料的加工情况,得出不同材料的能量密度阈值。提出了先镀膜再进行刻蚀光栅的加工工艺,解决了激光对材料的选择性问题。通过光栅的高斯能量与距离的关系,进一步分析了纳秒激光制作光栅的过程。在铝膜上制作出了频率为10线/mm的水平和正交光栅,光栅结构规则,节距稳定,可用于光学测量。(3)研究了飞秒激光制作微尺度光栅方法。采用飞秒激光刻蚀系统,在石英玻璃试件表面刻蚀光栅。研究了飞秒激光刻蚀点和线段的基础参数,分别刻蚀出直径为1?m的点和线段。分析了光栅加工机理,制作了频率为500线/mm的平行光栅。光栅频率表征分析表明,制作光栅的节距的最大误差为0.95%。飞秒激光制作的微尺度光栅可用于SEM云纹作表面结构表征及变形测量。(4)采用纳秒激光在镀膜试件上制作了微尺度光栅,并成功地进行了水平拉伸实验和V形裂纹拉伸实验。实验表明,采用纳秒激光可以将光栅方便地制作在试件表面微区上,结合光学测量方法可以实现微尺度的变形测量。
[Abstract]:With the development and application of micro-electromechanical system, the research of micro-mechanics has become a hot spot. Because of its advantages of non-contact, full-field and high precision, the method of photomechanical measurement has been widely used in deformation measurement of materials and structures in different fields. Grating, as an important sensor in deformation measurement, has attracted much attention. Therefore, how to locate the measurement area accurately and fabricate grating quickly has become an important problem. Different gate making methods have different advantages and limitations. Laser has very high instantaneous power, small heat affected zone, high quality and precision of micromachining. Compared with other grating fabrication methods, laser etching eliminates the process of making template and development, can be directly etched, the fabrication area can be adjusted, and the location is accurate. In this paper, nanosecond laser and femtosecond laser are used to fabricate micro-grating systematically. The main contents are as follows: (1) the geometric phase method (GPA) based on grating and scanning electron microscope (SEM) moire method are studied to characterize the structure of grating with different frequency and area. The method of grating frequency representation based on phase-based two-dimensional Fourier transform is deduced and simulated. The relationship between the amplification ratio and the reference gate frequency in SEM moire method is established. (2) the nanosecond laser fabrication method for micro-scale grating is studied. Starting with the basic etching line segments, the processing conditions of different materials are compared and analyzed, and the energy density threshold of different materials is obtained. The process of etching grating first by coating is put forward, and the problem of laser selectivity to materials is solved. The process of nanosecond laser grating fabrication is further analyzed by the relationship between Gao Si energy and distance of grating. Horizontal and orthogonal gratings with a frequency of 10 lines / mm have been fabricated on aluminum film. The grating structure is regular and the pitch is stable. (3) the fabrication method of micro-scale grating by femtosecond laser is studied. Femtosecond laser etching system was used to etch the grating on the surface of quartz glass specimen. The fundamental parameters of femtosecond laser etching point and line segment are studied. The processing mechanism of the grating is analyzed, and the parallel grating with a frequency of 500-wire / mm is fabricated. The analysis of the grating frequency shows that the maximum error of the pitch distance of the grating is 0.95. The micro-scale grating fabricated by femtosecond laser can be used to characterize the surface structure and measure the deformation of SEM moire. (4) the micro-scale grating is fabricated by nanosecond laser on the coated sample. The horizontal tensile test and V-shaped crack tensile test were successfully carried out. The experimental results show that the grating can be conveniently fabricated on the surface of the specimen by nanosecond laser, and the deformation measurement on the micro scale can be realized by combining the optical measurement method.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN25;TN249

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