基于Sagnac干涉仪的二阶关联光学相关识别

Second-order Correlated Optical Correlation Recognition in Sagnac Interferometer

本文从理论和实验上对基于Sagnac干涉仪的关联光学相关识别进行了分析和验证。本文使用赝热光源照射在Sagnac干涉仪中测得的强度分布,运用关联干涉算法,再对计算结果进行傅里叶变换得到相关输出结果。在实验中,通过一级亮斑测得物体偏离光轴的距离为387μm和486.5μm,并能测出物体横向位移的变化量为97.5μm,与物体实际的横向位移量相差2.5μm,测量误差较小。本文通过观察相关输出的一级亮斑实现高精度的百微米量级的光学相关识别﹐拓宽了光学相关识别的应用领域。

In this paper,the optical correlation recognition in a Sagnac interferometer with second-order correlation is analyzed and demonstrated theoretically and experimentally.The intensity distribution is recorded from the Sagnac interferometer irradiated by a pseudo-thermal light source.The intensity correlated interference is obtained with the recorded intensity and a further Fourier transform on the correlation results is executed.In the experiment,the distance from the optical axis of the object was measured as 387 μm and 486.5 μm by the first order bright spots.The change of the the object′s lateral displacement was measured as 97.5 μm,which was a small measurement error for 2.5 μm.In this paper,the hundred-micron optical correlation recognition is realized by observing the light spots of the output,and the distance of the object from the optical axis is measured.When the horizontal position of the object changes,the position of the primary bright spot changes with it.The changes of the lateral displacement can be measured,and the measurement accuracy is higher.It is to be hoped that our results will be of value not only to the application of optical correlation recognition and medical but also to military fields.