基于光纤振动幅度的激光散斑控制  

Laser speckle control based on fiber optic vibration amplitude

作　　者：贺锋涛[1] 左波[1] 张冠芳[1] 

机构地区：[1]西安邮电大学电子工程学院,陕西西安710121

出　　处：《西北大学学报（自然科学版）》2015年第1期28-30,共3页Journal of Northwest University（Natural Science Edition）

基　　金：国家自然科学基金资助项目(61201193);陕西省自然科学基金基础研究计划资助项目(2012JQ8014)

摘　　要：实验以单片机AT89C51为核心控制器件,采用AD9850型DDS器件产生幅度可调的正弦波信号,再经ULN2003驱动器音圈电机振动。通过控制光纤振动幅度实现了激光成像系统中激光散斑噪声的存在使得图像灰度剧烈变化,降低了图像分辨率,影响成像质量。本文以AT89C51单片机为核心控制器件,采用AD9850型DDS器件产生幅度可调的正弦波信号,再经ULN2003驱动器驱动音圈电机振动,通过光纤振动实现了激光成像系统中激光散斑噪声的控制。在电压幅度0～3.0V振动范围内,随着电压幅度增加,图像散斑的平均对比度整体趋势减小,并在电压幅度2.2V时平均对比度获得了最小值0.06,达到了良好的散斑控制效果。AT89C51, as the core control devices in the experiment, can be used to control the vibration of optical fiber through the adjustable amplitude sine wave signal that is generated by AD9850 DDS and the voice coil motor vibration from ULN2003 driver. The laser speckle noise is reduced by controlling fiber optic vibration amplitude. In the case of constant frequency and different voltage amplitude （ different vibration amplitude of fiber-optic）, the microscopic images of the polished glass surface are collected to analyze the speckle noise by calculating their average contrast ratio. Within the range of 0 - 3.0V of the voltage amplitude, the overall tendency of average contrast ratio of image speckles decreases with increasing of voltage amplitude, and reaches the minimum value that the voltage is 0. 15V by controlling the speckle noise. By controlling the fiber optic vibration amplitude it got good effect. The excellent performance of speckle control is achieved.

关 键 词：单片机 AD9850 散斑对比度 

分 类 号：TN249[电子电信—物理电子学]