Status of FIRST spectro-interferometer on SCExAO: sensitivity study and characterization of 5-telescopes visible photonics integrated circuits

The Fiber Imager foR a Single Telescope (FIRST) is a visible spectro-interferometer (600-760 nm, R~400) installed on the Subaru telescope's extreme adaptive optics platform (SCExAO). It provides high-precision spatial coherence measurements with high angular resolution (~8 mas at 656 nm, ~1% coherence accuracy) by combining light from sub-apertures of the telescope pupil. We present two upgrades of the instrument towards H𝛼 detection of protoplanets. We report on the integration of a new 4000-resolution spectrograph and on the sensitivity of the instrument. We also present the characterisation of a high performance visible photonic integrated circuit prototype used for the interferometric combination of 5 sub-apertures.