Prof. Niranjan Thatte

Abstract:

We present the SWIFT image slicer and its novel de-magnifying design. It is based on the MPE-3D and SPIFFI image slicers, uses plane mirrors to slice the input field, but achieves a considerable de-magnification through the use of a mosaic of spherical lenses. As only plane and spherical surfaces are used in the design, classical polishing techniques can be applied to achieve very high surface accuracy and quality. This reduces aberrations and scattered light, mandatory for an image slicer working at optical wavelengths and behind an adaptive optics system. Except for the lens mosaic, the SWIFT slicer is built entirely from Zerodur and is assembled using optical contacting. We present a detailed description of the design as well as results of the early stages of its fabrication.

Abstract:

We describe the design of a 2nd generation instrument for the ESO VLT which uses 24 cryogenic pickoff arms linked to diamond-machined image slicing integral field units to deliver a unique multiple deployable integral field capability in the near-infrared (1-2.5 mu m). The science requirements for the instrument are presented and linked to the functional specification. The baseline instrument concept is described with emphasis on technological innovations. (c) 2006 Elsevier B.V. All rights reserved.

Abstract:

SWIFT is an adaptive optics assisted integral field spectrograph covering the I and z astronomical bands (0.7-1.0 mu m) at a spectral resolving power R <= 5000. At its heart is an all-glass image slicer with high throughput based on a novel de-magnifying design allowing a compact instrument. SWIFT profits from two recent developments: (i) the improved ability of second generation adaptive optics systems to correct for atmospheric turbulence in SWIFTS's bandpass, and (ii) the availability of CCD array detectors with high quantum efficiency at very red wavelengths. It is a dedicated integral field spectrograph, specifically built to address a range of interesting astrophysical questions. (c) 2005 Elsevier B.V. All rights reserved.