A micropupil-based near-infrared imaging spectrograph

This paper describes a near infrared imaging spectrograph designed for very high throughput (30%), many spatial pixels (128x128), and a wide field of view (>1 arcminute). Each spectrum contains approximately twenty spectral channels. This balance between spatial and spectral coverage is driven by limited detector size and represents an excellent match to many astrophysical problems. We achieve the high efficiency and wide field of view by placing an array of microlenses in the focal plane wheel of a pre-existing camera/spectrograph. A narrow band filter prevents overlap of the individual traces. Ray tracing and preliminary tests at the telescope demonstrate the workability of the concept. Initial observations with the imaging spectrograph should take place soon after this conference.