Thanks for the link! I’ve been trying to figure out how to buy/make a Raman spectrometer for cheap (currently in a third world country too!). Have you built one yet? I’m having trouble finding the lenses needed (mostly because of my lack of knowledge). Any chance you know what to use?

Laser ($40): https://a.co/d/0wjNGBz

Diffraction grating ($12): https://a.co/d/6bpO8xm

Laser focusing lens: Not found

Fluorescence collection lens: Not found

Focusing lens: Not found

Collimating lenses: Not found