Hi-5 is the L'-band (3.5-4.0 mu m) high-contrast imager of Asgard, an instrument suite
in preparation for the visitor focus of the VLTI. The system is optimized for high-contrast
and high-sensitivity imaging within the diffraction limit of a single UT/AT telescope.
It is designed as a double-Bracewell nulling instrument producing spectrally-dispersed
(R=20, 400, or 2000) complementary nulling outputs and simultaneous photometric outputs
for self-calibration purposes. In this paper, we present an update of the project
with a particular focus on the overall architecture, opto-mechanical design of the
warm and cold optics, injection system, and development of the photonic beam combiner.
The key science projects are to survey (i) nearby young planetary systems near the
snow line, where most giant planets are expected to be formed, and (ii) nearby main
sequence stars near the habitable zone where exozodiacal dust that may hinder the
detection of Earth-like planets. We present an update of the expected instrumental
performance based on full end-to-end simulations using the new GRAVITY+ specifications
of the VLTI and the latest planet formation models.
