New technological developments in integral field spectroscopy

Abstract

Integral Field Spectroscopy (IFS) provides a spectrum simultaneously for each spatial sample of an extended two-dimensional field. Basically, the IFS is located in a telescope focal plane and is composed by an Integral Field Unit (IFU or image slicer) and a spectrograph. The IFU acts as a coupler between the telescope and the spectrograph by reformatting optically a rectangular field into a quasi-continuous pseudo-slit located at the entrance focal plane of the spectrograph. The Integral Field Units (IFUs) are presently limited either by their cost/risk (when manufactured with classical glass polishing techniques) or by their performances (when constituted by metallic components). Recent innovative methods, developed conjointly by LAM (Laboratoire d'Astrophysique de Marseille, France) and WinLight Optics (Marseille, France), allow reaching high performances (accurate roughness, sharp edges, surface form, etc.) with standard glass manufactured components while saving costs and time by an order of magnitude compared with classical techniques. Last developments (in term of design and manufacturing) and applications are presented in details in this article.