Bache M, Brambilla E, Gatti A, Lugiato L
Opt Express. 2004 Nov 29;12(24):6067-81. doi: 10.1364/opex.12.006067.
In ghost imaging schemes information about an object is extracted by measuring the correlation between a beam that passed the object and a reference beam. We present a spatial averaging technique that substantially improves the imaging bandwidth of such schemes, which implies that information about high-frequency Fourier components can be observed in the reconstructed diffraction pattern. In the many-photon regime the averaging can be done in parallel and we show that this leads to a much faster convergence of the correlations. We also consider the reconstruction of the object image, and discuss the differences between a pixel-like detector and a bucket detector in the object arm. Finally, it is shown how to non-locally make spatial filtering of a reconstructed image. The results are presented using entangled beams created by parametric down-conversion, but they are general and can be extended also to the important case of using classically correlated thermal-like beams.
在鬼成像方案中，通过测量穿过物体的光束与参考光束之间的相关性来提取关于物体的信息。我们提出了一种空间平均技术，该技术可大幅提高此类方案的成像带宽，这意味着在重建的衍射图样中可以观察到关于高频傅里叶分量的信息。在多光子 regime 中，平均可以并行进行，并且我们表明这会导致相关性更快地收敛。我们还考虑了物体图像的重建，并讨论了物体臂中像素状探测器和桶探测器之间的差异。最后，展示了如何对重建图像进行非局部空间滤波。结果是使用由参量下转换产生的纠缠光束呈现的，但它们具有普遍性，也可以扩展到使用经典相关的类热光束的重要情况。
