A New Solution for the Dispersive Element in Astronomical Spectrographs

TL;DR

This paper introduces a novel dispersive element for astronomical spectrographs that can significantly improve spectral resolution, demonstrated with an example achieving R=18,000 on the Keck telescope.

Contribution

The paper proposes a new dispersive element design that enhances spectral resolution in existing spectrographs, offering an upgrade path for moderate-resolution instruments.

Findings

Achieved spectral resolution of 18,000 with the new element on LRIS-R.

The solution maintains reasonable throughput under good seeing conditions.

Provides a practical upgrade method for existing spectrographs.

Abstract

We present a new solution for the dispersive element in astronomical spectrographs, which in many cases can provide an upgrade path to enhance the spectral resolution of existing moderate-resolution reflection-grating spectrographs. We demonstrate that in the case of LRIS-R at the Keck 1 Telescope a spectral resolution of 18,000 can be achieved with reasonable throughput under good seeing conditions.