Skip to main content

Research Repository

Advanced Search

Design of the VLT-CUBES image slicers: Field re-formatters to provide two spectral resolutions

Calcines, Ariadna; Wells, Martyn; O’Brien, Kieran; Morris, Simon; Seifert, Walter; Zanutta, Alessio; Evans, Chris; Di Marcantonio, Paolo

Design of the VLT-CUBES image slicers: Field re-formatters to provide two spectral resolutions Thumbnail


Martyn Wells

Walter Seifert

Alessio Zanutta

Chris Evans

Paolo Di Marcantonio


CUBES is a high efficiency spectrograph designed for a Cassegrain focus of the Very Large Telescope and is expected to be in operation in 2028. It is designed to observe point or compact sources in a spectral range from 300 to 405nm. CUBES will provide two spectral resolving powers: R≥20,000 for high resolution (HR) and R≥5,000 for low resolution (LR). This is achieved by using an image slicer for each resolution mode. The image slicers re-format a rectangular on-sky field of view of either 1.5arcsec by 10arcsec (HR) or 6arcsec by 10arcsec (LR) into six side-by-side slitlets which form the spectrograph slit. The slit dimensions are 0.19mm × 88mm for HR and 0.77mm × 88mm for LR. The on-sky and physical widths of the slicer mirrors are 0.25arcsec/0.5mm (HR) and 1arcsec/2mm (LR). The image slicers reduce the spectrograph entrance slit etendue and hence the size of the spectrograph optics without associated slit losses. Each of the proposed image slicers consists of two arrays of six spherical mirrors (slicer mirror and camera mirror arrays) which provide a straight entrance slit to the spectrograph with almost diffraction-limited optical quality. This paper presents the description of the image slicers at the end of the Phase A conceptual design, including their optical design and expected performance.


Calcines, A., Wells, M., O’Brien, K., Morris, S., Seifert, W., Zanutta, A., …Di Marcantonio, P. (2023). Design of the VLT-CUBES image slicers: Field re-formatters to provide two spectral resolutions. Experimental Astronomy, 55(1), 267-280.

Journal Article Type Article
Acceptance Date Aug 2, 2022
Online Publication Date Sep 5, 2022
Publication Date 2023-02
Deposit Date Sep 5, 2022
Publicly Available Date May 23, 2023
Journal Experimental astronomy.
Print ISSN 0922-6435
Electronic ISSN 1572-9508
Publisher Springer
Peer Reviewed Peer Reviewed
Volume 55
Issue 1
Pages 267-280
Public URL


Published Journal Article (1.4 Mb)

Publisher Licence URL

Copyright Statement
This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit

You might also like

Downloadable Citations