Preliminary design study of the integral field unit for the E-ELT Harmoni instrument

HARMONI is a visible and near-infrared (0.47 to 2.45 μm) integral field spectrograph over a range of resolving powers from R~3000 to R~20000. We will present in this paper, the different concepts of the HARMONI Integral Field Unit that makes the link between HARMONI Preoptics and the 4 Spectrographs. It is composed of a field splitter/relay system and an image slicer that creates from a rectangular Field of View a very long (532mm) pseudo-slit for each spectrograph. HARMONI is also considering a separate visible spectrograph and we present a possible image slicer for this option.