光学 精密工程, 2015, 23 (1): 83, 网络出版: 2015-02-15
改进的强度相干成像室内实验方法
Improved experiment method for intensity correlation imaging in laboratory
合成孔径成像 强度相干成像 空间频谱 相位恢复 赝热光 synthetic aperture imaging intensity correlation imaging spatial frequency spectrum phase retrieval pseudothermal light
摘要
设计了一种新的强度相干成像室内实验方法, 以简化现有强度相干实验过程, 获取接近实际观测的测量数据。首先, 分析了强度相干成像原理及影响成像质量的因素;介绍了现有强度相干成像实验方法并分析其存在的不足。然后, 利用赝热光源和CCD设计了一种新的强度相干成像方法;介绍了利用此种方法模拟强度相干成像的原理及特点。最后, 进行了室内强度相干成像实验, 验证了提出方法的可行性。实验结果表明: 利用提出的实验方法能够较好地测量目标的空间功率谱, 测量噪声主要分布在高频部分;当测量信噪比大于20时, 利用相位恢复方法可恢复获得较好的目标光强分布图像。实验显示, 提出的成像方法能够较好地模拟强度相干成像, 实验中能够较为方便地调节光强随机涨落并观测基线参数, 实现对小角直径目标的有效成像。
Abstract
An improved experiment method in a laboratory for intensity correlation imaging was designed to simplify the experiment processing of the intensity correlation imaging and to obtain measured data close to the actual observation. Firstly, the theory of intensity correlation imaging and its influencing factors on imaging quality were analyzed. Then,the existing intensity correlation imaging method and its disadvantages were discussed. A new experiment of intensity correlation imaging was designed and implemented by using a pseudothermal light and a CCD array, and the theories and characteristics to simulate the intensity correlation imaging by proposed method were introduced. Finally, the data analysis and imaging experiments were performed to verify the feasibility of the method. Experimental results indicate that the proposed method measures well the spatial power spectra of the objects, and the measurement noise mainly distributes in the high frequency region. Moreover, the intensity image of the object can be reconstructed by a phase retrieval algorithm when the signal-to-noise ratio is higher than 20.It concludes that this method preferably realizes the simulation of intensity correlation imaging. In the experiment, the adjustment of the intensity random fluctuation and the parameter of observing baseline are more convenient, so that the object with a small angular diameter is easy to be imaged.
高昕, 李希宇, 王斌, 吴元昊, 陆长明, 唐嘉. 改进的强度相干成像室内实验方法[J]. 光学 精密工程, 2015, 23(1): 83. GAO Xin, LI Xi-yu, WANG Bin, WU Yuan-hao, LU Chang-ming, TANG Jia. Improved experiment method for intensity correlation imaging in laboratory[J]. Optics and Precision Engineering, 2015, 23(1): 83.