Ultraviolet astronomical spectrograph calibration with laser frequency combs from nanophotonic lithium niobate waveguides
Abstract
Astronomical precision spectroscopy underpins searches for life beyond Earth, direct observation of the expanding Universe and constraining the potential variability of physical constants across cosmological scales. Laser frequency combs can provide the critically required accurate and precise calibration to the astronomical spectrographs. For cosmological studies, extending the calibration with such astrocombs to the ultraviolet spectral range is highly desirable, however, strong material dispersion and large spectral separation from the established infrared laser oscillators have made this exceedingly challenging. Here, we demonstrate for the first time astronomical spectrograph calibrations with an astrocomb in the ultraviolet spectral range below 400 nm. This is accomplished via chip-integrated highly nonlinear photonics in periodically-poled, nano-fabricated lithium niobate waveguides in conjunction with a robust infrared electro-optic comb generator, as well as a chip-integrated microresonator comb. These results demonstrate a viable route towards astronomical precision spectroscopy in the ultraviolet and may contribute to unlocking the full potential of next generation ground- and future space-based astronomical instruments.
Keywords
Cite
@article{arxiv.2306.13609,
title = {Ultraviolet astronomical spectrograph calibration with laser frequency combs from nanophotonic lithium niobate waveguides},
author = {Markus Ludwig and Furkan Ayhan and Tobias M. Schmidt and Thibault Wildi and Thibault Voumard and Roman Blum and Zhichao Ye and Fuchuan Lei and François Wildi and Francesco Pepe and Mahmoud A. Gaafar and Ewelina Obrzud and Davide Grassani and Olivia Hefti and Sylvain Karlen and Steve Lecomte and François Moreau and Bruno Chazelas and Rico Sottile and Victor Torres-Company and Victor Brasch and Luis G. Villanueva and François Bouchy and Tobias Herr},
journal= {arXiv preprint arXiv:2306.13609},
year = {2025}
}