LINC-NIRVANA: optical design of an interferometric imaging camera

Combining the two 8.4 m telescopes of the Large Binocular Telescope 1(LBT) offers the unique possibility to achieve diffraction limited images with 23 m spatial resolution. This requires an interferometric superposition of the two telescope beams in a Fizeau-type interferometer. LINC-NIRVANA delivers a 10 arcsec x 10 arcsec panoramic field of view with 5 mas pixel size. In addition to delivering diffraction limited, single-telescope images, the optics have several additional constraints imposed by interferometric operation. In this paper, we describe the evolution of the optical design and how the individual optical subsystems were developed in parallel to provide optimal combined performance. We also present an alignment strategy to setup the optics and to achieve zero optical path difference.

[1]  John M. Hill,et al.  The Large Binocular Telescope project , 2004, SPIE Astronomical Telescopes + Instrumentation.

[2]  R. Ragazzoni.  Pupil plane wavefront sensing with an oscillating prism , 1996 .

[3]  Roberto Ragazzoni,et al.  LINC-NIRVANA: how to get a 23-m wavefront nearly flat , 2004, SPIE Astronomical Telescopes + Instrumentation.

[4]  W A Traub,et al.  Combining beams from separated telescopes. , 1986, Applied optics.

[5]  Peter Bizenberger,et al.  The LINC-NIRVANA cryogenic interferometric camera , 2004, SPIE Astronomical Telescopes + Instrumentation.

[6]  Roberto Ragazzoni,et al.  The LINC-NIRVANA interferometric imager for the Large Binocular Telescope , 2004, SPIE Astronomical Telescopes + Instrumentation.