The fiber link conveys the light from the polarized beams coming out of the Cassegrain polarimeter into the cryogenic spectrograph.
This link consists of a dual 45m circular fluoride fiber custom-made with purified material to ensure a throughput better than 90% over the entire spectral range of SPIRou.
This fiber link also includes a pupil slicer at spectrograph entrance to minimize injection losses while maintaining the desired spectrograph resolution.
The last section of the fiber link includes octogonal fibers ensuring a high stability of the input image at the spectrograph entrance.