Stephanie Rossini-Bryson

The GLINT instrument: high-contrast imaging of stellar companions using nulling interferometry.

Directly imaging habitable-zone exoplanets and analysing their spectra can reveal atmospheric compositions and potential biosignatures, making this endeavour a central goal in exoplanet science. However, separating the faint planetary light from its host star is extremely challenging, requiring high contrasts and tight angular separations. Nulling Interferometry offers a solution by destructively interfering light from an on-axis host star, while constructively interfering light from its companion, effectively ‘nulling out’ the starlight. The Guided Light Interferometric Nulling Technology (GLINT) instrument, downstream of the SCExAO system on the 8.2-meter Subaru Telescope (Hawai’i, USA), performs nulling interferometry in the H-band. GLINT uses photonic technology with laser-inscribed waveguides to couple light within a glass chip and has previously resolved angular separations 2.5 times smaller than the telescope’s diffraction limit. Recently, GLINT underwent a major upgrade in its optical design and installation of a new chip to enhance sensitivity. This upgraded version of GLINT will be tested on-sky mid-September 2024, aiming to demonstrate its scalable capabilities for future use on larger-class telescopes and long-baseline interferometers. Here, we present an overview of the GLINT instrument, current achievements, and future endeavours.