Vipa-based Instrument for Oxygen Loaded Atmospheres (VIOLA) for VLT2030 and beyond

Understanding the chemical composition of exoplanet atmospheres is key to identifying habitable worlds and potential biosignatures. Current instruments face challenges in detecting weak atmospheric signals from small-sized exoplanets due to telluric contamination, spectral overlap, and limited resolution. To address this, we are developing VIOLA (Vipa-based Instrument for Oxygen Loaded Atmosphere), a compact, high-throughput, ultra-high-resolution spectrograph designed to target the J (1.1–1.3 μm) and H (1.45–1.65 μm) bands in a single exposure, with an additional channel for simultaneous stellar monitoring. VIOLA uses a Virtually Imaged Phased Array (VIPA) as its primary disperser, reaching a spectral resolution of R = 300,000, enabling the detection of key atmospheric molecules such as O2, CH4, CO2, CO, H2O, OH, and HCN around nearby M-dwarf super-Earth, sub-Neptune exoplanets from a ground-based observatory. By combining innovative optics with a flexible design compatible with multiple front ends, VIOLA will bridge the gap between current ground-based facilities and future ELT-class instruments. This development aligns with ESO's long-term strategy for the VLT and VLTI to remain at the forefront of astrophysics in the ELT era, enabling experimental exobiology in exoplanet atmospheres