All-spherical telescope with extremely wide field of view

TL;DR

This paper proposes an all-spherical catadioptic telescope design capable of wide sky monitoring with a large field of view and discusses its optical performance and potential applications.

Contribution

It introduces a novel all-spherical telescope system with wide fields of view up to 40 degrees, demonstrating high optical performance despite the curved focal surface.

Findings

Aperture up to 800 mm with 30° and 40° fields of view.

Focal spot size of 1.4'' - 1.9'' for 30° field.

Focal spot size of 2.2'' - 2.9'' for 40° field.

Abstract

An all-spherical catadioptic telescope with the angular field of view of several tens of degrees in diameter and spherical focal surface is proposed for the monitoring of large sky areas. We provide a few examples of such a system with the apertures up to 800 mm and the field of view $30^\circ$ and $40^\circ$ in diameter. The curvature of the focal surface is repaid by high performance of the telescope. In particular, the diameter of a circle, that includes 80% of energy in the polychromatic image of a star, is in the range $1.4'' - 1.9''$ across the field of $30^\circ$ size and $2.2'' - 2.9''$ for the field of $40^\circ$ size. Some ways of working with curved focal surfaces are discussed.