一种提高时间平均数字全息测振条纹模式对比度的方法  

A Method to Improve Fringe Contrast in Time-average Digital Holography for Vibration Measurement

作　　者：肖文[1] 张旭红[1] 潘锋[1] 丛琳[1] 李艳[1] 

机构地区：[1]北京航空航天大学仪器科学与光电工程学院,北京100191

出　　处：《光子学报》2015年第3期58-62,共5页Acta Photonica Sinica

基　　金：国家自然科学基金(No.61177006)资助

摘　　要：针对基于时间平均数字全息法的微振动原位检测,提出了一种有效提高振动条纹模式对比度的方法,进而可准确获得待测面振幅分布.首先针对实际振动过程中物体存在纵向微位移而引起的相位误差进行校正;然后去除记录过程中物光场散斑引起的相位噪音,有效提高了被第一类零阶贝塞尔函数调制的条纹对比度;最后利用第一类零阶贝塞尔函数的变化规律和条纹级数,定量估计全场的振幅分布.搭建了以声波作为激励源的时间平均全息测振实验系统,采用频率分别为0、1 100、2 000和9 000 Hz的正弦声波激励簧片进行实验验证.结果表明,以振动频率2 000Hz为例,本方法能够有效提高振动调制条纹质量,并计算得到三级零点处的振幅值分别为109.4nm、244.2nm、356.4nm,与理论值相比较,误差分别为6.31%、3.34%和3.78%,在允许范围之内,证明了该方法的有效性.A new algorithm was proposed to improve vibration-related fringes contrast for micro-vibration online detection based on time-average digital holography. First, phase change arising from the longitudinal micro-displacement of the object during vibrating process was corrected. Then phase noise caused by speckle noise was eliminated, and thus fringes pattern contrast that modulated by Bessel function was improved effectively. Finally, the amplitude distribution of the measuring surface was estimated according to Bessel function and fringe progressions. An experimental system based on time- average digital holographic interferometry was proposed for micro-vibration measurement that acoustic wave was used for excitation source. The experiment was verified by the reed that excited at the sinusoidal frequency of 0, 1 100, 2 000 and 9 000 Hz, respectively. The result based on vibration frequency of 2 000 Hz shows that the proposed method can improve vibration-related fringes contrast effectively. Amplitude of three-order zero points are 109.4 nm, 244.2 nm and 356.4 rim, and errors are 6.31%, 3. 34% and 3. 78%, respectively, compared with theoretical values, which demonstrate the effectiveness of the method within the allowable range.

关 键 词：全息应用 时间平均法 贝塞尔函数 簧片 条纹模式 高对比度显示 振幅分布 

分 类 号：O438.1[机械工程—光学工程] TN247[理学—光学]