Characterization and on-sky testing of photonic, AWG-based astronomical spectrographs
arXiv:2607.26954
The paper presents the characterization of arrayed‑waveguide grating (AWG) photonic chips and their on‑sky testing with a high‑resolution near‑infrared spectrograph prototype, demonstrating observations of bright stars to evaluate photonic spectroscopy for compact astronomical instruments.
Abstract
Astrophotonics is a field that intends to meet the needs of next-generation instruments at a small footprint, low cost, and high stability, compared to bulk-optics-based alternatives. Much development effort is driven by the stringent requirements of direct detection and characterization of exoplanets. Our team works in characterizing Arrayed-Waveguide Grating (AWG) chips for photonics-based, high-resolution, near infrared spectro-interferometry. AWG spectrographs allow to test the feasibility of photonic spectro-interferometers for exoplanet characterization, another step towards fully photonic instruments for astronomy. We present the current status of our AWG characterization and a preliminary on-sky qualification campaign at the PAPYRUS AO system. We present the CoLiBRIS-AWG spectrograph prototype built for on-sky testing, and preliminary results using our high-resolution (H band, R~18000) AWG for observations of Arcturus (alpha Boötes) and Betelgeuse (alpha Orionis). This work contributes to assessing the capabilities of photonic spectroscopy for the development of future compact instruments.
11 pages, 9 figures; Proc. SPIE 14148, Optical and Infrared Interferometry and Imaging X, 14148-95