Chen TianBao, Zeng XueFeng, Bai YingYing, Zhang Zhiyu, Wang YongJin, Zhang Feng, Zhang XueJun
Opt Express. 2021 Nov 22;29(24):39256-39270. doi: 10.1364/OE.444421.
The burgeoning field of astrophotonics, the interface between astronomy and photonics, is redefining astronomical instrumentation to replace traditional bulk optical systems with integrated optics. This drives the development of a new promising photonics-integrated interferometric imaging technique, called the segmented planar imaging detector for electro-optical reconnaissance (SPIDER). Compared to conventional imaging systems, SPIDER can reduce the size, weight, and power (SWaP) by one to two orders of magnitude for an equivalent imaging resolution in virtue of photonics-integrated technology. However, SPIDER has a dense lens distribution and tens of separated narrow wavebands demultiplexed by array waveguide gratings. In this paper, we developed a new simplified sparse-aperture photonics-integrated interferometer (SPIN) imaging system. The SPIN imaging system was no more a Michelson configuration interferometer as SPIDER and was designed as a Fizeau configuration interferometer imaging system. This transfer of configuration type affords a more concise structure; the SPIN was designed with much less apertures and fewer wavebands than those of SPIDER. Further, the SPIN yields enhanced modulation transfer function and imaging quality with equivalent aperture diameter, compared with SPIDER. The main barrier of this transfer is the elimination of coupling restriction at the tip of a waveguide, namely the apodization effect. This effect, which is caused by the coupling effect between Fourier lens and waveguide, hinders SPIN imaging systems from getting finer resolution. However, a microscope could be used to eliminate this effect. Moreover, a waveguide array is used to receive these finer details and enlarges the field of view in SPIN. The coupling efficiency of the waveguides and crosstalk errors between waveguides of array were analyzed, which are important for proper parameters setting in SPIN imaging system. Based on these analyses, the imaging principle was derived and a hyper-Laplacian-based imaging reconstruction algorithm was developed. A simulation of the SPIN imaging system with seven apertures and one imaging waveband demonstrated the high imaging quality.
天体光子学这一新兴领域，即天文学与光子学的交叉领域，正在重新定义天文仪器，用集成光学取代传统的体光学系统。这推动了一种新的、有前景的光子集成干涉成像技术的发展，即用于电光侦察的分段平面成像探测器（SPIDER）。与传统成像系统相比，借助光子集成技术，对于同等成像分辨率，SPIDER可将尺寸、重量和功耗（SWaP）降低一到两个数量级。然而，SPIDER具有密集的透镜分布以及由阵列波导光栅解复用的数十个分离的窄波段。在本文中，我们开发了一种新的简化稀疏孔径光子集成干涉仪（SPIN）成像系统。SPIN成像系统不再像SPIDER那样是迈克尔逊配置干涉仪，而是被设计为菲佐配置干涉仪成像系统。这种配置类型的转变提供了更简洁的结构；与SPIDER相比，SPIN设计时的孔径和波段要少得多。此外，在等效孔径直径下，SPIN与SPIDER相比具有更高的调制传递函数和成像质量。这种转变的主要障碍是消除波导尖端的耦合限制，即变迹效应。这种效应由傅里叶透镜与波导之间的耦合效应引起，阻碍SPIN成像系统获得更高的分辨率。然而，可以使用显微镜来消除这种效应。此外，在SPIN中使用波导阵列来接收这些更精细的细节并扩大视场。分析了波导的耦合效率以及阵列中波导之间的串扰误差，这对于SPIN成像系统的正确参数设置很重要。基于这些分析，推导了成像原理并开发了基于超拉普拉斯的成像重建算法。对具有七个孔径和一个成像波段的SPIN成像系统的模拟展示了高成像质量。
