Ground-based near-infrared astronomy is severely hampered by the forest of atmospheric emission lines resulting from the rovibrational decay of OH molecules in the upper atmosphere. The extreme brightness of these lines, as well as their spatial and temporal variability, makes accurate sky subtraction difficult. Selectively filtering these lines with OH suppression instruments has been a long standing goal for near-infrared spectroscopy. We have shown previously the efficacy of fibre Bragg gratings combined with photonic lanterns for achieving OH suppression. Here we report on PRAXIS, a unique near-infrared spectrograph that is optimised for OH suppression with fibre Bragg gratings. We show for the first time that OH suppression (of any kind) is possible with high overall throughput (18 per cent end-to-end), and provide examples of the relative benefits of OH suppression.
@article{arxiv.2001.04046,
title = {First demonstration of OH suppression in a high efficiency near-infrared spectrograph},
author = {S. C. Ellis and J. Bland-Hawthorn and J. S. Lawrence and A. J. Horton and R. Content and M. M. Roth and N. Pai and R. Zhelem and S. Case and E. Hernandez and S. G. Leon-Saval and R. Haynes and S. S. Min and D. Giannone and K. Madhav and A. Rahman and C. Betters and D. Haynes and W. Couch and L. J. Kewley and R. McDermid and L. Spitler and R. G. Sharp and S. Veilleux},
journal= {arXiv preprint arXiv:2001.04046},
year = {2020}
}