The GLINT instrument: an integrated photonic nulling interferometer

Directly imaging exoplanets remains a significant challenge due to the overwhelming brightness of their host stars and the limitations of ground-based telescopes in contrast and angular resolution. Nulling interferometry is an effective technique for suppressing starlight while allowing the fainter signal from an orbiting planet to pass through. This technique is at the core of the Guided Light Interferometric Nulling Technology (GLINT) instrument, installed at the Subaru Telescope in Hawaii. GLINT uses an integrated optics beam combiner with three single-mode input waveguides in a triangular geometry. 3D-printed microlenses on a black chrome mask is used to optimize light injection. The beam combiner includes phase shifters and tricouplers for simultaneous nulling and fringe tracking, providing 12 outputs for photometry and interferometry, which are fibre coupled and directed into a CRED1 camera for detection.