A Near-Infrared, On-Chip Astrophotonic Spectrograph with a Resolving Power of 40,000

High-resolution spectrographs are essential for major astronomical science cases such as characterizing exoplanet atmospheres, stellar kinematics, chemistry, and probing the mechanisms of the cosmic baryon cycle in the era of extremely large telescopes (ELTs). However, as the telescope diameter grows, the volume, mass, and cost of conventional bulk optics spectrographs on them grow as D2 (D = telescope diameter). The large (several tens of m
²
) footprints of conventional bulk-optics spectrographs on the ELTs will pose a significant challenge to the thermo-mechanical stability of high-resolution spectrographs, thus reducing their effective precision.