Spectrograph design for the Asgard/BIFROST spectro-interferometric instrument for the VLTI [IMA]

http://arxiv.org/abs/2208.05397


The BIFROST instrument will be the first VLTI instrument optimised for high spectral resolution up to R=25,000 and operate between 1.05 and 1.7 $\mu$m. A key component of the instrument will be the spectrograph, where we require a high throughput over a broad bandwidth. In this contribution, we discuss the four planned spectral modes (R=50, R=1000, R=5000, and R=25,000), the key spectral windows that we need to cover, and the technology choices that we have considered. We present our plan to use Volume Phase Holographic Gratings (VPHGs) to achieve a high efficiency $>$ 85%. We present our preliminary optical design and our strategies for wavelength calibration.

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S. Chhabra, M. Frangiamore, S. Kraus, et. al.
Thu, 11 Aug 22
55/68

Comments: SPIE conference proceedings 2022