CARMENES. II: optical and opto-mechanical design

CARMENES is a fiber-fed high-resolution echelle spectrograph for the Calar Alto 3.5m telescope. The instrument is built by a German-Spanish consortium under the lead of the Landessternwarte Heidelberg. The search for planets around M dwarfs with a radial velocity accuracy of 1 m/s is the main focus of the planned science. Two channels, one for the visible, another for the near-infrared, will allow observations in the complete wavelength range from 550 to 1700 nm. To ensure the stability, the instrument is working in vacuum in a thermally controlled environment. The optical design of both channels of the instrument and the front-end, as well as the opto-mechanical design, are described.