dispersive spectrometer 

https://doi.org/10.1351/goldbook.08240
Spectrometer in which electromagnetic radiation is separated spatially into its component wavenumbers by a dispersive element, such as a prism or a diffraction grating.
Source:
PAC, 2021, 93, 647. (Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)) on page 656 [Terms] [Paper]