Prime focus wide-field corrector designs with lossless atmospheric dispersion correction

TL;DR

This paper introduces wide-field corrector designs for several telescopes that incorporate a novel atmospheric dispersion correction method using movable lenses, achieving high correction quality without added surfaces or absorption.

Contribution

The paper presents a new concept for atmospheric dispersion correction using lateral lens movements, integrated into Terezibh-style wide-field correctors for multiple telescopes.

Findings

Effective atmospheric dispersion correction without additional surfaces.

Designs suitable for fiber spectroscopy and wide-field imaging.

Simple mechanism with minimal actuators for lens movement.

Abstract

Wide-Field Corrector designs are presented for the Blanco and Mayall telescopes, the CFHT and the AAT. The designs are Terezibh-style, with 5 or 6 lenses, and modest negative optical power. They have 2.2-3 degree fields of view, with curved and telecentric focal surfaces suitable for fiber spectroscopy. Some variants also allow wide-field imaging, by changing the last WFC element. Apart from the adaptation of the Terebizh design for spectroscopy, the key feature is a new concept for a 'Compensating Lateral Atmospheric Dispersion Corrector', with two of the lenses being movable laterally by small amounts. This provides excellent atmospheric dispersion correction, without any additional surfaces or absorption. A novel and simple mechanism for providing the required lens motions is proposed, which requires just 3 linear actuators for each of the two moving lenses.