Collaborative Research: Mastering the photonic lantern: The key to transformative diffraction-limited spectroscopy

该项目旨在推进一项名为“光子灯笼”的关键技术。光子灯笼将使大型望远镜后面的光谱仪变得紧凑和稳定。这些光谱仪将提供对各种天文物体的极其精确的测量，最明显的是其他恒星周围的行星。推进光子灯笼的工作将在几个关键方面进行。首先，了解如何使用灯笼有效地从大型望远镜捕捉光线。第二，证明灯笼在受到地球大气层的影响后，可以感知光波的形状。这将实现对这些形状误差的校正，并最大限度地增加捕获的光量。最后，探索使用灯笼拍摄图像和测量天文物体位置的潜力。这项工作也将直接适用于电信和自由空间光通信。灯笼可以在增加数据量和与卫星传输数据的保真度方面发挥关键作用。在衍射极限下工作，打破了传统的能见度有限的仪器定标法则，使光谱仪在给定的规格下成为最紧凑的。紧凑型仪器使用的光学元件更容易制造，质量更高，对机械变形更坚固，更容易热稳定，而且成本更低。光子灯(PL)允许将多模光纤输入转换为多个单模光纤，从而在输入处实现更大的耦合，同时保持对光谱仪的衍射限制，从而保持超稳定的谱线扩展函数(即，形状不随时间或输入照明条件而变化)。该项目试图了解如何有效地将光从经过自适应光学部分校正的波前注入PL。它还将进一步研究PL是否可以用作焦平面波前传感器，消除非公共路径和色度误差，并提高系统效率。最后，将研究通过分离电场的相干和非相干部分来使用灯笼进行成像和天体测量的能力。该项目的结果可能会立即对大型望远镜上现有的和未来的光谱仪产生重大影响。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project aims to advance a key technology known as a “photonic lantern.” Photonic lanterns will allow for compact and stable spectrographs behind large telescopes. These spectrographs will deliver extremely precise measurements of various astronomical objects, most notably planets around other stars. The work to advance photonic lanterns will proceed in several key ways. First, to understand how to use lanterns to efficiently capture light from a large telescope. Second, to demonstrate that lanterns can sense the shape of light waves after they are affected by Earth’s atmosphere. This will enable correction for those shape errors and maximize the amount of light captured. Finally, to explore the potential of using a lantern for making images and measuring positions of astronomical objects. This work will also be directly applicable to telecommunications and free-space optical communications. Lanterns could play a key role in increasing the data volume and fidelity of data transfer with satellites. Operating at the diffraction-limit breaks traditional seeing-limited instrument scaling laws and allows a spectrograph to be the most compact for a given set of specifications. A compact instrument uses optics that are more likely to be manufacturable and of higher quality, is more robust to mechanical deflections, easier to thermally stabilize, and costs less. A Photonic Lantern (PL) allows conversion of a multi-mode fiber input to multiple single-mode fibers, thus enabling greater coupling at the input while maintaining the diffraction-limit into the spectrograph thus maintaining an ultra-stable spectral line-spread function (i.e. the shape does not vary with time or input illumination conditions). The project seeks to understand how to efficiently inject light into PLs from wavefronts partially corrected by adaptive optics. Further it will investigate if PLs can be used as focal-plane wavefront sensors, eliminating non-common path and chromatic errors, and boosting system efficiency Finally, the ability to use lanterns to do imaging and astrometry by separating the coherent and incoherent parts of the electric field will be investigated. The outcomes from this project could have immediate significant impact on existing and future spectrographs on large telescopes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.