Experimental study of an advanced concept of moderate-resolution holographic spectrographs

TL;DR

This paper presents an experimental study of a novel moderate-resolution holographic spectrograph that achieves high spectral resolution and throughput, offering a cost-effective alternative to existing spectrographs for astrophysical applications.

Contribution

The study demonstrates a new holographic spectrograph design with R up to 5000 and 55% throughput, showing its competitiveness and potential for astrophysical use.

Findings

Spectral resolving power exceeds R>4000.

Throughput reaches 55%, matching models.

The concept is a cost-effective alternative to existing spectrographs.

Abstract

We present the results of an experimental study of an advanced moderate-resolution spectrograph based on a cascade of narrow-band holographic gratings. The main goal of the project is to achieve a moderately high spectral resolutionwith R up to 5000 simultaneously in the 4300-6800 A visible spectral range on a single standard CCD, together with an increased throughput. The experimental study consisted of (1) resolution and image quality tests performed using the solar spectrum; and (2) a total throughput test performed for a number of wavelengths using a calibrated lab monochromator. The measured spectral resolving power reaches values over R>4000 while the experimental throughput is as high as 55%, which is in good agreement with the modeling results. Comparing the obtained characteristics of the spectrograph under consideration with the best existing spectrographs, we conclude that the used concept can be considered a very competitive and cheap alternative to the existing spectrographs of the given class. We propose several astrophysical applications for the instrument and discuss the prospect of creating its full-scale version.