The design of an apochromatic optical spectrograph for astronomical purposes

Abstract An optical spectrograph for use in the OGS (Optical Ground Station), a 1 m telescope in Izana Observatory (Tenerife, Spain) and the GTC telescope at Islas Canarias observatory has been designed, built and tested. The dispersive part was designed and built at the Centro de Investigaciones en Optica, A.C. Due to requirements from Instituto Astrofisico de Canarias this Spectrograph has an f /5 collimator and camera with a plate factor of 6.55 nm/mm. Since the resolution of the system has to have a high resolution of the order of 15 μm or less, an apochromatic design was selected. This article describes this design and its main characteristics.