Study on a Large-Scale Phase Delay Compensation System for Long-Baseline Stellar Interferometry

Long baseline stellar interferometry is a key method for achieving high spatial resolution in astronomy, contributing to a wide range of astrophysical research. Current developments focus on extending baseline lengths to enhance resolution, increasing telescope numbers for better imaging, and enlarging apertures to improve sensitivity. The foundation of this technique lies in time and phase synchronization: time synchronization ensures simultaneous observation by multiple telescopes, while phase synchronization aligns the light signals' phases to extract information from interference patterns. This paper focuses on the critical step of large-scale phase delay compensation. A 40 cm short-distance phase delay compensation system is designed to meet the scheme's requirements. Using spatial coherence and white light interference principles, the phase compensation is validated through experimental data, demonstrating the feasibility of large-scale compensation. The system also accounts for fixed optical path differences between asymmetrically distributed telescopes and path variations due to Earth's rotation during extended observations.