The telescope simulator for the Fraunhofer telescope Wendelstein

J. Erhardt; F. Grupp; H. Kellermann; F. Lang; C. Gössl; F. Kummer; F. Langaßner; U. Hopp; R. Bender

doi:10.1117/12.2676662

5 October 2023 The telescope simulator for the Fraunhofer telescope Wendelstein

J. Erhardt, F. Grupp, H. Kellermann, F. Lang, C. Gössl, F. Kummer, F. Langaßner, U. Hopp, R. Bender

Proceedings Volume 12680, Techniques and Instrumentation for Detection of Exoplanets XI; 126801R (2023) https://doi.org/10.1117/12.2676662
Event: SPIE Optical Engineering + Applications, 2023, San Diego, California, United States

Conference Poster

Abstract

The 2.1 m-telescope at Mt.Wendelstein in the German Alps will be equipped with an upgraded multi-focal station, distributing the telescope light of one of the Nasmyth ports to either a high-resolution radial velocity instrument, a Shack-Hartmann wavefront sensor or a three-channel-imager. For feeding calibration light to both, the Shack-Hartmann Sensor and the fiber-fed high-resolution spectrograph, a diffraction-limited telescope simulator is used. This simulator mimics the angular distribution of light (secondary mirror vignetting) of the telescope in order to excite the same modes in the fiber feed as the” real” telescope. This is necessary to allow for m/s calibration by means of an astro frequency comb. As 1 m/s corresponds to about 1/2000 of a 13.5 μm pixel on the R=60000 spectrograph, modal effects are crucial and small changes in the illumination of the fiber have an imprint on the calibration accuracy that can be achieved in simultaneous calibration mode. With this paper we introduce the optical layout of the telescope simulator and its opto-mechanical design, taking into account the space constraints at one of our Nasmyth ports of the telescope. The wavefront performance is verified utilizing a Shack-Hartmann sensor. And it is verified that the system is tolerant to small alignment inaccuracies allowing for a relatively relaxed co-alignment of the telescope simulator and the telescope. Our tests in the laboratory prior to installation of the telescope simulator show small wavefront errors and prove that the optical system of the telescope simulator meets all requirements, including a performance that is diffraction limited (Marechal limit: RMS ⪅ λ/14).

Citation Download Citation

J. Erhardt, F. Grupp, H. Kellermann, F. Lang, C. Gössl, F. Kummer, F. Langaßner, U. Hopp, and R. Bender "The telescope simulator for the Fraunhofer telescope Wendelstein", Proc. SPIE 12680, Techniques and Instrumentation for Detection of Exoplanets XI, 126801R (5 October 2023); https://doi.org/10.1117/12.2676662

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available