Abstract

GIANO-TNG is a cryogenic cross-dispersed spectrometer designed to operate at near IR wavelengths (0.9-2.5 ?m) achieving a resolving power of R approximately equal to 50,000 and covering most of the spectral range in a single exposure. The core of its optical system consists of a 3-mirror anastigmat (TMA) used in double pass, which acts both as collimator and camera. Thanks to its all-mirrors design, the system is intrinsically achromatic and can be conveniently aligned at optical wavelengths. This papers describes the procedure followed and the results obtained for the alignment of the optics of this instrument.