The Gemini Near-Infrared Imager (NIRI)

This paper presents the basic design of the Gemini Near-Infrared Imager (NIRI) and discusses its capabilities. NIRI offers three different pixel scales to match different operating modes of the Gemini telescope and allows polarimetric and spectroscopic observations. It is equipped with an infrared on-instrument wave-front sensor (OIWFS) to allow tip-tilt and focus correction even in highly obscured regions. The science detector array is an Aladdin II InSb 1024 x 1024 pixel device sensitive from 1.0 to 5.5 mum.