Silicon photonic aperture synthesis for long baseline near-infrared interferometry

For Very Long Baseline Interferometry high-resolution imaging of exoplanets, an astrophotonic-based aperture synthesis concept is proposed for high-resolution direct imaging of exoplanets. A silicon photonic chip incorporates microheaters and optical phase shifters for precise control of delays and phase synchronization from widely separated receivers. A satellite laser guide star with a modulated optical signal serves as a global phase reference, enabling high-speed, high-stroke phase compensation and combining. The chip's design addresses challenges such as atmospheric turbulence and phase stability in optical frequencies. The study outlines the current proof-of-concept instrument status, measured performance, chip fabrication, and routes towards photonics-enabled exoplanet imaging.