Mix and match as you go: beam switch module that splits wavelengths, scrambles beams, and switches fibers in multiplexed replicated astronomical spectrograph systems such as VIRUS2

The Extremely Large Telescopes (ELTs) are promising a profound transformation of our understanding of the universe through large-scale surveys of a myriad of previously unseen astronomical objects across cosmic space-time. For such surveys, the ELTs will need highly multiplexed spectrographs that can super-efficiently target multiple objects at a variety of spatial scales across broad spectral ranges. This can be enabled by (or at least can benefit from) a dedicated device that streamlines this “mix and match” process between different spatial samples at the telescope focus and different kinds of back-end spectrographs by splitting wavelengths to appropriate channels, scrambling beams to maximum spectral PSF stability, and switching between fibers or fiber-integral-field-units. The Beam-Switch Module (BSM), being developed for the VIRUS2 instrument at the McDonald Observatory, is one possible blueprint of such a system and this paper details its design and recent prototype results.