Preparation of the calibration unit for LINC-NIRVANA

We present in this paper the status of the calibration unit for the interferometric infrared imager LINC-NIRVANA that will be installed on the Large Binocular Telescope, Arizona. LINC-NIRVANA will combine high angular resolution (~10 mas in J), and wide field-of-view (up to 2'×2') thanks to the conjunct use of interferometry and MCAO. The goal of the calibration unit is to provide calibration tools for the different sub-systems of the instrument. We give an overview of the different tasks that are foreseen as well as of the preliminary detailed design. We show some interferometric results obtained with specific fiber splitters optimized for LINC-NIRVANA. The different components of the calibration unit will be used either during the integration phase on site, or during the science exploitation phase of the instrument.