Benirschke David J, Han Ningren, Burghoff David
Department of Electrical Engineering, University of Notre Dame, Notre Dame, IN, USA.
Google LLC, Mountain View, CA, USA.
Nat Commun. 2021 Jul 9;12(1):4244. doi: 10.1038/s41467-021-24471-4.
Multiheterodyne techniques using frequency combs-radiation sources whose lines are perfectly evenly-spaced-have revolutionized science. By beating sources with the many lines of a comb, their spectra are recovered. Even so, these approaches are fundamentally limited to probing coherent sources, such as lasers. They are unable to measure most spectra that occur in nature. Here we present frequency comb ptychoscopy, a technique that allows for the spectrum of any complex broadband source to be retrieved using a comb. In this approach, the spectrum is reconstructed by unfolding the simultaneous beating of a source with each comb line. We demonstrate this both theoretically and experimentally, at microwave frequencies. This approach can reconstruct the spectrum of nearly any complex source to high resolution, and the speed, resolution, and generality of this technique will allow chip-scale frequency combs to have an impact in a wide swath of new applications, such as remote sensing and passive spectral imaging.
使用频率梳（其谱线间距完全均匀的辐射源）的多外差技术彻底改变了科学。通过将源与梳状的多条谱线进行拍频，可以恢复它们的光谱。即便如此，这些方法从根本上仅限于探测诸如激光之类的相干源。它们无法测量自然界中出现的大多数光谱。在此，我们展示了频率梳叠层成像技术，这是一种能够使用频率梳来获取任何复杂宽带源光谱的技术。在这种方法中，通过展开源与每条梳状谱线的同时拍频来重建光谱。我们在微波频率下通过理论和实验证明了这一点。这种方法能够以高分辨率重建几乎任何复杂源的光谱，并且该技术的速度、分辨率和通用性将使芯片级频率梳在诸如遥感和被动光谱成像等广泛的新应用中发挥作用。
