Performance limits of astronomical arrayed waveguide gratings on silica platform

Abstract

We present a numerical and experimental study of the impact of phase errors on the performance of large, high-resolution Arrayed Waveguide Gratings (AWG) for applications in astronomy. We use a scalar diffraction model to study the transmission spectrum of an AWG under random variations of the optical waveguide lengths. We simulate phase error correction by numerically trimming the lengths of the optical waveguides to the nearest integer multiple of the central wavelength. The optical length error distribution of a custom-fabricated silica AWG is measured using frequency-domain interferometry and Monte-Carlo fitting of interferogram intensities. In the end, we give an estimate for the phase-error limited size of a waveguide array manufactured using state-of-the-art technology. We show that post-processing eliminates phase errors as a performance limiting factor for astronomical spectroscopy in the H-band.

arXiv comment14 pages, 13 figures; to be published in Optics Express

References in corpus (3)

• Characterization and on-sky demonstration of an integrated photonic spectrograph for astronomy
• First starlight spectrum captured using an integrated photonic micro-spectrograph
• Instruments without optics: an integrated photonic spectrograph

Cited by in corpus (5)

• 2023 Astrophotonics Roadmap: pathways to realizing multi-functional integrated astrophotonic instruments
• Potential of commercial SiN MPW platforms for developing mid/high-resolution integrated photonic spectrographs for astronomy
• Custom Arrayed Waveguide Gratings with Improved Performance
• Design, simulation and characterization of integrated photonic spectrographs for Astronomy I: Generation-I AWG devices based on canonical layouts
• Simulating the Study of Exoplanets Using Photonic Spectrographs