Adaptive optics fed single-mode spectrograph for high-precision Doppler measurements in the near-infrared

We present the design for a high resolution near-infrared spectrograph. It is fed by a single-mode fiber coupled to a high performance adaptive optics system, leading to an extremely stable instrument with high total efficiency. The optical design is a cross-dispersed Echelle spectrograph based on a white pupil layout. The instrument uses a R6 Echelle grating with 13.3 grooves per mm, enabling very high resolution with a small beam diameter. The optical design is diffraction limited to enable optimal performance; this leads to subtle differences compared to spectrographs with large input slits.