Proof of concept for a basic visible light monochromator

White light from a basic 5mm LED shines onto a cheap replica transmission grating (1000 lines/mm), which projects the diffraction pattern through the aperture. Rotating the lid assembly and slit allows you to select specific wavelength regions.

Simple design but I was able to achieve ~5nm resolution after narrowing the exit slit with razor blades, although the intensity wasn't amazing. Tested the resolution on my DIY spectrophotometer (published on my Thingiverse profile)

Creality

Ender 3 Pro

No

0.3

20