A simple spectroscope: the grating and slit are evidenced.

History of spectroscopy - Wikipedia

Two-color synchrotron X-ray spectroscopy based on transverse resonance island buckets

Possible Echelle grating optical configurations. Echelle grating has

Schematic diagram of a simple spectroscope.

Double-slit time diffraction at optical frequencies

Basics of spectrometers and spectroscopy

Spectroscopy on the go: Innovations in the design of portable broadband spectrometers

Schematics of the constructed spectrometer showing the simple design

Double Axis Diffraction Grating Material, Spectra: Educational Innovations, Inc.

Optical Spectroscopy of Glass

Design a spectrograph

PDF) Research-Based Proposals on Optical Spectroscopy and Secondary Students' Learning Outcomes