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Proceedings Paper

Fiber IFU unit for the second-generation VLT spectrograph KMOS
Author(s): Daigo Tomono; Harald Weisz; Reiner Hofmann
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Paper Abstract

KMOS is a cryogenic multi-object near-infrared spectrograph for the VLT. It will be equipped with about 20 deployable integral field units (IFUs) which can be positioned anywhere in the 7.2 arcmin diameter field o the VLT Nasmyth focus by a cryogenic robot. We describe IFUs using micro lens arrays and optical fibers to arrange the two-dimensional fields from the IFUs on the spectrograph entrance slit. Each micro-lens array is mounted in a spider arm which also houses the pre-optics with a cold stop. The spider arms are positioned by a cryogenic robot which is built around the image plane. For the IFUs, two solutions are considered: monolithic mirco-lens arrays with fibers attached to the back where the entrance pupil is imaged, and tapered fibers with integrated lenses which are bundled together to form a lens array. The flexibility of optical fibers relaxes boundary conditions for integration of the instrument components. On the other hand, FRD and geometric characteristics of optical fibers leads to higher AΩ accepted by the spectrograph. Conceptual design of the instrument is presented as well as advantages and disadvantages of the fiber IFUs.

Paper Details

Date Published: 7 March 2003
PDF: 8 pages
Proc. SPIE 4841, Instrument Design and Performance for Optical/Infrared Ground-based Telescopes, (7 March 2003); doi: 10.1117/12.459901
Show Author Affiliations
Daigo Tomono, Max-Planck-Institut fur extraterrestrische Phyik (Germany)
Harald Weisz, Ingenieurburo fur den Maschinenbau Weisz (Germany)
Reiner Hofmann, Max-Planck-Institut fur extraterrestrische Physik (Germany)


Published in SPIE Proceedings Vol. 4841:
Instrument Design and Performance for Optical/Infrared Ground-based Telescopes
Masanori Iye; Alan F. M. Moorwood, Editor(s)

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