IFS spectrograph designs for the Wide-field Spectroscopic Telescope: Architecture and performance gains from curved sensors

TL;DR

This paper proposes a spectrograph architecture for the WST IFS, exploring curved sensors to enhance performance, reduce complexity, and guide future large-scale spectrograph development.

Contribution

It introduces a novel spectrograph design utilizing curved sensors to improve efficiency and simplify layout for the WST IFS.

Findings

Curved sensors can reduce aberrations and simplify spectrograph layout.

The proposed architecture achieves high throughput and image quality.

Curved sensors offer a promising pathway for future large-scale IFS instruments.

Abstract

The Wide-field Spectroscopic Telescope (WST) is a proposed 12-meter segmented facility optimized for seeing limited observations in the visible and designed to operate both a high-multiplex multi-object spectrograph and a panoramic integral field spectrograph (IFS). The WST IFS concept builds on instruments such as MUSE at the VLT (Very Large Telescope), using field splitters and image slicers to reformat a large field into pseudo-slits feeding spectrographs with two optimized spectral channels. This paper presents the spectrograph architecture developed for the WST IFS, aiming to achieve high through put and image quality over a wide wavelength range in a cost-effective manner. We investigate the use of curved detectors as a means to simplify the spectrograph layout, reduce aberrations, and potentially improve efficiency. This study establishes a promising baseline for the IFS spectrographs and assesses the benefits of incorporating curved sensors that can guide the development of future large-scale integral field spectrographs.