A high-sensitivity near-infrared science combiner for MROI

We report on the design and performance of a 6-way multi-wavelength beam combining instrument for the MRO Interferometer, allowing for fringe measurements at any of the J/H/K near-infrared bands at switchable spectral resolution with high sensitivity. Three preliminary designs for the instrument are presented and compared. The results of an ongoing evaluation performed on the performance, costs, and risks of each designs are analysed. Signal-to-noise analyses confirm in particular the utility of one of the design at magnitudes as faint as K=13.