HARMONI & ELT: prototyping and testing the spectrograph TMA collimator alignment procedure

Matthias Tecza; Edgar Castillo-Dominguez; James Kariuki; Elliot Meyer; Eduard Muslimov; Zeynep Ozer; Niranjan Thatte; Fraser Clarke; John Capone

doi:10.1117/12.3019873

18 July 2024 HARMONI & ELT: prototyping and testing the spectrograph TMA collimator alignment procedure

Matthias Tecza, Edgar Castillo-Dominguez, James Kariuki, Elliot Meyer, Eduard Muslimov, Zeynep Ozer, Niranjan Thatte, Fraser Clarke, John Capone

Author Affiliations +

Proceedings Volume 13096, Ground-based and Airborne Instrumentation for Astronomy X; 130964U (2024) https://doi.org/10.1117/12.3019873
Event: SPIE Astronomical Telescopes + Instrumentation, 2024, Yokohama, Japan

Conference Poster

Abstract

HARMONI is the first light, adaptive optics assisted, visible and near-infrared integral field spectrograph for the European Southern Observatory’s Extremely Large Telescope (ELT). It covers a large spectral range from 450 nm to 2450 nm with spectral resolving powers R ≡ λ/δλ from 3300 to 17000 and spatial sampling from 60 mas to 4 mas. It contains four identical spectrograph modules that collimate, disperse, and image the long slit at the exit of the integral field unit onto the science detectors. The collimation optics comprises of a three mirror anastigmat, using off-axis, aspheric mirrors. Previously we simulated an iterative alignment procedure that uses interferometric wavefront measurements together with a numerical optical model to minimise the wavefront error by adjusting a set of compensators. In this paper we demonstrate the feasibility of this procedure with an off-axis parabolic mirror as a prototype collimator, that has the same number of compensators as the HARMONI collimators. We show that we achieve a sufficiently low wavefront error within a few iterations of alignment. We cooled the test setup in a cryostat and obtained preliminary wavefront measurements at a cryogenic temperature of 130 ˚K, demonstrating the athermal design of the prototype.

(2024) Published by SPIE. Downloading of the abstract is permitted for personal use only.

Citation Download Citation

Matthias Tecza, Edgar Castillo-Dominguez, James Kariuki, Elliot Meyer, Eduard Muslimov, Zeynep Ozer, Niranjan Thatte, Fraser Clarke, and John Capone "HARMONI & ELT: prototyping and testing the spectrograph TMA collimator alignment procedure", Proc. SPIE 13096, Ground-based and Airborne Instrumentation for Astronomy X, 130964U (18 July 2024); https://doi.org/10.1117/12.3019873

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