Rai Mani Ratnam, Rosen Joseph
Opt Lett. 2021 Apr 1;46(7):1712-1715. doi: 10.1364/OL.417765.
The concept of an optical incoherent synthetic aperture is widely used in astronomical interferometric telescopes. In this Letter, we propose a new, to the best of our knowledge, method to realize optical incoherent synthetic aperture imaging. The method is based on a superposition of optical transfer functions of incoherent imaging systems. Only two small sub-apertures, out of a much larger full synthetic aperture, are open at any given time, and they transfer light from the observed object to the image sensor. During the imaging process, the two sub-apertures move over the full synthetic aperture, where the gap between them starts from zero and grows with time. For every position of the pair of sub-apertures, two images are captured. In one of the images, the sub-apertures have the same phase value, and in the other image, one of the sub-apertures is phase shifted by radian relative to the other one. The final image with the image resolution of the synthetic aperture is obtained as a superposition of the entire recorded images. Optical experiments are performed on reflective objects, and results of the synthetic aperture-based method demonstrate an imaging performance similar to that of direct imaging by a system with a single aperture of the size of the synthetic aperture.
光学非相干合成孔径的概念在天文干涉望远镜中被广泛应用。在本信函中，据我们所知，我们提出了一种实现光学非相干合成孔径成像的新方法。该方法基于非相干成像系统光学传递函数的叠加。在任何给定时刻，在大得多的全合成孔径中仅有两个小子孔径打开，它们将来自观测物体的光传输到图像传感器。在成像过程中，这两个子孔径在全合成孔径上移动，它们之间的间隙从零开始并随时间增大。对于这对子孔径的每个位置，采集两幅图像。在其中一幅图像中，子孔径具有相同的相位值，而在另一幅图像中，其中一个子孔径相对于另一个子孔径相移了π弧度。具有合成孔径图像分辨率的最终图像通过叠加所有记录的图像获得。对反射物体进行了光学实验，基于合成孔径方法的结果表明其成像性能与具有合成孔径大小的单孔径系统的直接成像性能相似。
