显微数字全息图相位的滤波法提取

显微数字全息的关键技术之一是其相位信息的提取。通过分析显微数字全息图的空间频谱特点,提出了一种新的相位提取方法。将数字全息图频谱进行搬移,使物光频谱中心移到频域坐标原点;设计有限脉冲响应(FIR)数字滤波器滤出物光频谱;求解滤波后信号的辐角得到全息图相位。对设计的实验系统进行了验证,实验结果表明采用提出的方法提取显微数字全息相位,完全可行,效果良好。

Extracting phase information of microscopy digital holography with filter

Extraction of phase information is one of the key technologies in microscopy digital holography. The character of spatial spectrum of microscopy digital hologram is analyzed and then a novel method for extracting phase is proposed. The center of object spectrum is moved to the origin of spatial frequency domain. A finite impulse response (FIR) filter is designed, with which the object spectrum is obtained. The phase information of hologram is achieved by calculating the argument of filtered signal. An experimental system is created and the validity of the proposed method is proved. The experimental results show the feasibility of the method.